Grade 8 Science and Technology Textbook (Nepal) PDF

Science and Technology Grade 8 Government of Nepal Ministry of Education, Science and Technology Curriculum Development Centre Publisher: Government of Nepal Ministry of Education, Science and Technology...

Science and Technology Grade 8 Government of Nepal Ministry of Education, Science and Technology Curriculum Development Centre Publisher: Government of Nepal Ministry of Education, Science and Technology Curriculum Development Centre Sanothimi, Bhaktapur © Curriculum Development Centre All rights reserved, no part of this publication may be reproduced, transmitted in any other form or by any means without the written permission of the publisher. However, this does not prohibit making photocopies of its pages for teacher training or other non-profit making purposes. First Edition: 2023 Send your comment and suggestions to: Editing and Publishing Section, Curriculum Development Centre Phone: 01-6630-588, Fax: 01-6630-797 Email: [email protected] Website: moecdc.gov.np  Preface School education is the foundation for preparing the citizen who are loyal to the nation and nationality, committed to the norms and values of federal democratic republic, self-reliant and respecting the social and cultural diversity. It is also remarkable for developing a good moral character with the practical know-how of the use of ICT along with the application of scientific concept and positive thinking. It is also expected to prepare the citizens who are moral and ethical, disciplined, social and human value sensitive with the consciousness about the environmental conversation and sustainable development. Moreover, it should be helpful for developing the skills for solving the real life problems. This textbook 'Science and Technology, Grade 8' is fully aligned with the intent carried out by the National Curriculum Framework for School Education, 2076 and is developed fully in accordance with the new Basic Level Science and Technology Curriculum, 2077. This textbook is initially written by Mr. Dambaru Prasad Pokhrel, Mrs. Rabina Maharjan, Mr Ram Sharan Regmi, Mr. Yubaraj Adhikari and Mr. Lav Dev Bhatta. It has been translated by Mr. Surendra Jung Karki, Mr. Mukti Subedi and Mr. Subash Kharel. The contribution made by Director General Mr. Baikuntha Prasad Aryal, Prof. Dr. Krishna Bhakta Maharjan, Dr. Kamal Prasad Acharya, Mrs. Pramila Bhakati, Mr. Uma Nath Lamsal, Mr. Heramba Raj Kandel, Mr. Keshar Bahadur Khulal, Mr. Shailesh Bahadur Pradhan and Mrs. Mina Shrestha is remarkable in bringing the book in this form. The language of the book has been edited by Mr. Arjun Prakash Bhusal. Art editing of this book was done by Mr. Shreehari Shrestha by making it four colour. The Curriculum Development Centre extends sincere gratitude to all of them. The textbook is a primary resource for classroom teaching. Considerable efforts have been made to make the book helpful in achieving the expected competencies of the curriculum. Curriculum Development Centre always welcomes constructive feedback for further betterment of its publications. 2080 BS Curriculum Development Centre Sanothimi, Bhaktapur  Contents Unit Topic Page 1 Scientific Learning 1 2 Information and Communication Technology 18 3 Living Beings and Their Structure 55 4 Biodiversity and Environment 89 5 Life Process 112 6 Force and Motion 152 7 Energy in Daily Life 185 8 Electricity and Magnetism 227 9 Matter 250 10 Materials Used in Daily Life 277 11 The Earth and Universe 302  Scientific Learning Scientific Learning Activities like observation, testing, survey, project work and model building are done for scientific learning. Such activities are done inside or outside the laboratory.Fact, theories and rules of science are discovered based on these activities. Safety precautions should be taken in laboratory work to avoid accidents. Such precautions also help to obtain correct results fron1 scientific expedn1ents, observations or research. 1.1 Precautions to be taken while Performing Experimental work in the Science Laboratory A n otice with the signs shown in the figure is pasted in the science lab. What precautions do these signals indicate? Discuss with your friends in the class. A science laboratory is a special room for conduc ting various scientific studies and experimental activities. Necessary equipment @ and ch emicals for scientific studies and research are available there. Various facts, theories, objects and substances related to science are Ix studied, observed, tested and used in the school's science laboratory. We sh ould pay attention to safety w hile doing such work. In the ® -~ ~ science lab, we must follow safety Fig: 1. 1 ~ rules. Science a nd Technology, Grade 8 1 Random scientific work without following safety measures nlay cause accidents as well as affect the results of observations, tests and experiments. Figure: 1.2 Observation of Mushroom Cultivation and Experimental work in the laboratory The following safetyrules must be followed while doing experimental work in a science laboratory: (a) The materials should not be handled haphazardly. (b) Masks, gloves and goggles should be worn while using harmful chemicals. (c) An apron or a lab coat must be put on while working in the laboratory. (d) Everyone should be aware of the emergency exit. (e) Hands should be was hed thoroughly with soap after the experimental work. (f) Eating and drinking should not be done in the laboratory. (g) Chemicals must not be tasted or smelled in the lab. (h) No playing and teasing in the laboratory. (i) The prescribed method shoul d be used while performing experimental work in the laboratory. (j) Special care should be taken while using a burner or touching hot objects in the laboratory. (k) Hot equipment should not be placed directly on the table during the experimental works. 2 Science and Techn ology, Grade 8 1.2 Experimental works in Science Fig: 1.3 Experimental works in the laboratory Observe the pictures and discuss L What are the students doing in the picture? ii. Which experiment have you done in the science laboratory? ui. What should you pay attention to when you are in the science laboratory'? iv. Why is science laboratory important? Experimentation is an act of drawing conclusions by using science process skills like observations, research, tests and model making in order to verify different theories and principles. If the desired results are not obtained through experiments in science, other alternatives are appliedto achieve it. Experimental work inay be done in the laboratory or outside but the safety measures listed above should be followed at any time. Observation Mamta was walking in the garden. She saw different kinds of colourful flowers in the garden. Since she has already learned about different parts of a flower in class, she picked a flower and looked at it. She slowly took out each part of the flower carefully to see the four parts of the flower one by one. In the beginning, she took out a calyx, corolla, androecium and gynoecium. Then she became clear about what was taught in class. Science and Technology, Grade 8 3 In a meantime, she noticed a caterpillar Uhusilkira)sitting on a leaf of the same plant and eating it. Man1ta was amused.She had studied in the previous classes that a caterpillar turns into a pupa and then to a butterfly. Therefore, she thought of keeping the caterpillar in a glass jar to observe if it turns into a butterfly. She slowly plucked the leaf along with the caterpillar, took it home and kept it safely in a jar without closing the lid. She gave soft leaves for food everyday and continuedobserving the changes. The caterpillar developed into a pupa after 15 to16 days.The caterpillar did not eat leaves after this. Thirteen to 14 days later, a yellow butterfly with black spots on the wings emerged. Man1ta shared all these observations with her friends and the science teacher. The teacher explained that observations like that of Mamta play an important role while studying science. The process of experiencing an object, event or process very carefully using the sense organs is called observation. Sense organs are used in observation. In cases where observation with our sense organs is - difficult, various tools such as hand lensesj microscopes etc. are used. Observe the given experiment for instance; Activity 1.1 Fig 1.4 Observation of the Title : Observation of Fungi experimental work Objective:To study the structure of fungi Material required: Bread, water, forceps or tongs, a glass slide, a coverslip and a microscope Method: i. Take a piece of bread. ii. Sprinkle some water on it and keep it covered in a moist place ni. Sprinkle a little water every day. iv. You will see fungi growing after a few days. Place a drop of methylene blue on the glass slide and put one of the mycelia in the drop with the help of forceps or tongs, cover it with the cover slip and observe it under the microscope. 4 Science and Techn ology, Grade 8 v. Observe the structure of fungi and draw its figure in your practical file and list the characteristics of fungi based on it. Any object is observed and experienced by seeing with the eyes, hearing with the ears, smelling with the nose, touching with the skin and tasting with the tongue. Observation is not limited to the laboratory. The rules, principles and characteristics of science can be studied by observing various natural and artificial objects, processes and events around the school and h01ne. Apart fro1n that, some laws and principles related to science can be observed even by visiting zoos, botanical gardens, pharmaceutical companies and information communication companies. When observing, it should be clear which object, process or event is to be observed. Accordingly, the purpose of observation should be determined. Similarly, it should be clear about what to observe and how to present the information obtained. In general, the report should be written after the observation work. There can be different formats for writing a report. For example. the report for activity 1.1 can be written as follows : Fig 1.5 Structure of fungi Title Observation of Fungi Objective: To study the stTucture of fungi Material required: Bread, water, forceps or tongs, glass slide, inicroscope Method: (i) The bread was taken. (ii) Every day a little water was sprinkled on it and kept covered in a inoist place. (iii) Fungi appeared on the bread after a few days. The fungus was placed on a slide of glass with the help of forceps or Science and Technology, Grade 8 5 tongs and was observed under a microscope to study the structure of a fungus. Result of the Observation The following characteristics were identified while observing the fungi: i. No green pigments were seen in them. 11. Root-like mycelia were seen. 111. Stem-like hyphae were observed. iv. Sporangia were observed on the tips of long branches growing from hyphae. Precautions i. Be careful when using forceps as they are sharp. 11. Avoid the fungus getting into your mouth and eyes. Activity 1.2 Prepare a report based on observation of permanent slides of single- celled organisms like an amoeba, paramecium and euglena with the help of a microscope in a science lab. Scientific test It is not possible to get all the information about a subject matter, process or event only by observation. We make various assumptions based on observations. A certain scientific procedure is followed in or outside the laboratory to check whether the assumption is correct or not. The scientific investigation performed in this way is called a test. For example, perform the test given below. Activity 1.3 Title: Test of Acids, Bases and Salts Objective:To identify the given substances whether they are acids, bases or salts with the help of indicators. Materials required: Lemon juice, soap water, salt water, red litmus paper, blue litmus paper, and test tubes. Method i. Keep lemon juice, soap water and salt water in separate test tubes. 6 Science and Techn ology, Grade 8 11. Dip a red and blue litmus paper respectively in a test tube containing lemon juice and observe the change in the litn1us paper. 111. Similarly, repeat the same process for soap water and salty water. Observation: Record the results of the reaction on the Practical file: Indicators Lemon juice Soap water Saltwater Red litmus paper Blue litmus paper Conclusion: Red litmus with lemon juice shows.......colour and blue litmus shows....... colour. Red litmus with soap water shows... colour and blue litmus shows......... colour. Red litmus with salt water shows....... colour and blue litmus show...... colour. Hence,........................ is an acid,..................... a base and...................... is salt. Determining whether the substances given in activity 1.3 are acids, bases or salts are not possible by observation only. One can only guess from the observation of the given activity. In the scientific learning process, inference or assumption is also called a hypothesis. Testing is the act of checking whether a hypothesis is true or not. Testing in science is also a kind of experimental work. It should be clear what is going to be tested and what is our assumption before any test. It should be clear about the purpose and process of testing with necessary materials, and the format to present the information obtained after testing. A report should be written after the test work. There may be different formats for writing the reports. A sample format of the report writing is given below. Title: Test of acids, bases and salts. Objective: To separate the given substances as acids, bases and salts with the help of indicators. Materials Required: Len1011 juice, soap water, salt water, indicators Science and Technology, Grade 8 7 (red and blue litmus paper) and test tubes. Method (i) The given substance was placed in three separate test tubes. (ii) Changes in the colour of red and blue lihnus paper were observed by dipping in lemon juice, soapy water and salt water one by one. Observations Indicators Lemon juice Soap water Salt water Red litmus No change Blue No change in paper in colour colour Blue litmus Red No change in No change in paper colour colour Conclusion:........... is acid as it turns blue litmus paper to red colour.,......... is a base as it turns red litmus paper into blue colour, and........ should be neutral because no colour change was observed. Activity: 1.4 Write a report with the help of a teacher, after testing the fact that salt and water are formed by the chemical reaction of acid and base. Activity 1.5 Two new students from class 8 are going to the science lab to do experimental work. What suggestions would you give them about the precaution they should take while working in the laboratory? Prepare a chart about the suggestions given and demonstrate it in class. 1.3 Research work Any research begins with a question or a curiosity. Generally, research is a study in depth or to find an answer to a question or curiosity. All the discoveries made are the achievements of such studies and research. While researching, the researcher has to patiently study a subject by completing a certain procedure. Even if you fail many 8 Science and Techn ology, Grade 8 thnes, you should try again by finding the weaknesses and improving on them. You have to follow different scientific inethods while conducting research work. Phases of the Research Work The following steps are generally followed in carrying out research work: a. Goal setting. b) Making inferences or hypotheses. a. Choice of the data collection inethod. c) Preparation of required materials. d) Data collection e) Analysis of data f) Conclusion Read the given dialogue Rusa What are you thinking about, Samprit? Samprit Yesterday, the teacher said that the manure used in the fields causes water pollution. I did not understand that. Manure is applied to the fields for the plants and how does it pollute water? Rusa Can plants take all the fertilizers applied in the fields? Samprit Perhaps not. Rusa Where does the manure that is not absorbed by the plants go? Samprit Rainwater, perhaps will wash it away. Rusa Where w ill the rainwater take it away? Samprit They may bring it to the rivers, lakes and ponds. Rusa In this way, excess fertilizer on the plant is washed away with rainwater into rivers, lakes, and ponds, and Science and Technology, Grade 8 9  it causes the growth of algae there. The increased algae take up dissolved oxygen in the water and oxygen will be deficient for aquatic animals. Samprit What you said may be correct, but I am still not convinced how algae develops due to the manure swept away by rainwater. Rusa So let's have an inquiry or conduct research work. Activity 1.6 Research question: What factors affect the growth of algae? Objective: To explore the role of chemical fertilizers and acids in the development of algae. Materials required: Pond water containing algae, three bottles, chemical fertilizers , vinegar etc. Method i. Bring algae-containing water from a nearby pond. 11. Now pour an equal amount of algae containing water into three glass bottles so that they are half filled. iii. Do not add anything in the first bottle, put a little chemical fertilizer in the second bottle and a little vinegar in the third bottle respectively. Name it accordingly from the outside. iv. Observe the growth of algae at the interval every five days. v. Write a conclusion based on the results obtained in 15 to 20 days. Observation: Fig: 1.6 Observation of the growth of algae 10 Scien ce an d Techn ology, Grade 8 Fill in the table below with the results obtained based on the observations: Date Growth of algae in the Growth of a]gae in the Growth of algae in the first bottle second bottle third bottle Conclusion: Chemical fertilizers play a........role and acids play a..... role in the growth of algae. Its report should be written after research work. There may be different formats for w riting a report. The report of the research work can be written as follows: Research Title: Effects of chemical fertilizers and acids on the growth of algae. Objective: To find out the role of chemical fertilizers and acids in the growth of algae. Materials required: pond water containing algae, three glass bottles, che1nical fertilizer, and vinegar. Method i. Water containing algae was brought from a nearby pond. IL Three glasses were half filled with an equal amount of water. iii. Only pond water containing algae was kept in the first bottle and pasted a sticker named pond water. iv. A little chemical fertilizer was kept in the second bottle and pasted a sticker named water containing chemical fertilizer. v. A little vinegar was placed in the third glass bottle and pasted a sticker named water containing vinegar. Observation: Science and Technology, Grade 8 11 The following results w ere obtained by observing at an interval of every five days. Dale Growth of algae Growth of algae in Grow th of algae in the first bottl e the second bottle in the third bottle Initial condition The number of algae in all three bottles was almost the same. After 15-20 days Th e growth of The growth of algae Algae started to algae is seen to is faster compared die. some extent. to the first bottle. Conclusion: Chemical fertilizers p lay a positive role in the growth of algae while acids play a negative role. Activity 1. 7 Which absorbs more heat among white and black colour? Prepare a report and present it to the class by deriving a conclusion after a brief research on the subject. 1.4 Survey The process of collecting data related to a topic or problen1 directly and deriving a conclusion is called a survey. Questionnaires , interviews, discussions and observations are th e guidelines for collecting data while doing a survey focu sing on a problen1 or a subject. In this way, conclusions are drawn after analyzing the collected data, and solutions to the issues or problems are obtained. Generally , the survey work is completed by following th e steps given below. a) Selection of objective b) Choice of data collection method c) Collection of data d) Analysis of data e) Conclusion 12 Science and Techn ology, Grade 8 A report is prepared including the title of the study, the purpose of the study, tools or methods of data collection, analysis of the collected data and finally conclusions and suggestions are written after completing the survey work by following the above steps. Activity 1.8 Perform a survey about solid waste management by visiting at least 50 houses in your com111unity. Prepare a questionnaire for the survey. Analyze the collected data and prepare a report with conclusions and necessary suggestions Sample of Survey Report Writing The sample of survey report writing which has been done in activity 1.8 and can be written as follows: Title: A study on solid waste management in one of the villages of Kathmandu. Background The surveyed area is a culttrrally rich village located in the inner city of Kath1nandu. There are many temples, monasteries and archaeological monuments in this village. People do business, office jobs and farming for living. Solid waste has emerged as a problem in this village due to the modern lifestyle. In this survey, study was done to find out how the people living here manage the solid waste that c0111es out of their houses daily. It is expected that the findings from this survey also help in the management of solid waste in other areas too. Objective: To study solid waste management in the study area. Data Collection Method: A questionnaire was developed to collect data on solid waste management, and 50 households were selected for the survey. Necessary data was collected based on the prepared questionnaire. Science and Technology, Grade 8 13 Analysis of Data: From the analysis of collected data, it was found that 50 percent of houses used to throw solid wastes into ni.unicipality vehicles without separating degradable and non-degradable, 30 percent of houses used to separate degradable wastes and make compost manure and the remaining 20 percent used to utilize degradable waste for making compost manure and the non-degradable to make various materials. The obtained results are presented in a bar diagram. non seperated making composte making composte manure from manure degradeab/e waste and other things from non degdrab/e waste Fig: 1.7 Conclusion: The results obtained from the above survey show that the practice of recycling and reusing solid wastes has started in the survey area. Annex 1 : Survey Questionnaire 1. What do you do with the solid waste that comes out of your house? a) Give it to waste collection agencies. b) Manage some of the waste at home and give the rest to the waste collection agencies. 14 Science and Techn ology, Grade 8  c) All wastes are managed at home. 2. What do you do with biodegradable waste? a) Make compost manure from it. b) Throw it on the road or in the river. c) Hand it over to waste-collectors. 3. What do you do with non-biodegradable garbage? a) Use it to make different materials. b) Collect and give it to the collection agency. c) Burn or bury it. Activity 1.9 Prepare a report by surveying at least 30 individuals or families through interviews, questionnaires or any other means on the various methods they use to preserve food materials. Science and Technology, Grade 8 15 Exercise 1. Choose the correct alternatives. a) What is the process of experiencing an object, event or process carefully through the sense organs? (i) test (ii) hypothesis (iii) curiosity (iv) observation b) Which of the following methods is suitable if one has to study whether the farmers of a region use more chemical or organic fertilizers? (i) observation (ii) test (iii) research (iv) survey c) Which of the following would you stop your friend from doingin the laboratory? (i) Tasting or smelling laboratory chemicals. (ii) Wearing a lab coat. (iii) Boiling water in a beaker. (iv) Using test tube holder while heating it. d) What should be done while performing a chemical reaction that produces fumes? (i) Hands should be kept away. (ii) It should be carried out on a table. (iii) It should be kept on a stand. (iv) It should be carried in a hood. e) Which is the first step of a scientific study? (i) investigation (ii) observation (iii) testing (iv) experimentation 16 Science and Techn ology, Grade 8 2. Distinguish between: (a) Observations and tests (b) Research and survey 3. Write the reason: a) Precautions should be taken while conducting experimental work. b) A report is prepared after the experiment and survey are done. c) Observation is the first step in scientific learning. 4. Write the answers to the given questions: a) What is observation? b) What is the importance of observation in scientific work? c) What is done in scientific work when there is not enough infonnation from observation? d) What precautions should be taken while carrying out a scientific experiment? e) List the things that should be done and should not be done while working in the laboratory. f) Whatshould we pay attention to while researching'? g) In what conditions is the survey conducted? h) What is meant by survey tools? Write with examples. i) Elina is interested to study the requirements of sunlight for green plants. Suggest a clear method for her how to conduct that study. j) A class had to be conducted in the absence of the science teacher in grade eight. Prepare a worksheet for conductin a practical class on the study of plant and animal cells. Science and Technology, Grade 8 17  Information and Communication Technology Modern information and communication technology and scientific advancen1ents have simplified and increased the efficiency of human life. Our daily lives are made easier, more instinctive and spontaneous by information and communication tools including the computer, internet, digital camera, CC camera (Closed Circuit ca1nera), radio, television etc. Similarly, information and communication equipment like ATMs. photocopiers, scanners, printers, routers, and Wi-Fi devices have made human livesmore efficient, smarter and practical. With the development of technologies, the use of Artificial intelligence (AI), virtual reality, robotics and cloud computing are also increasing day by day. For the accountability of online transactions, the Computer Code of Conduct. cyber law, and other aspects of Internet security should be followed strictly. In this chapter, we will discuss the application of these ICT tools. computing l.a ptop router n.,h drive / use drive natbed scanner ( tso memoty suck tipec»/ly BIE) POA dlgt~I ca....,. MP3 pr.,.. Fig 2. 1 Information and Communication Devices 18 Science nnd Technology. Grade 8 2.1 Tools of Inforn1ation and Communication Technology Radio Wireless Sets Television Computer I Fig 2.1 ICT Tools Information and communication technology refers to theintegrated tools of communication. Radio, television, newspapers, computer, projectors etc. are the tools of information and communication technology. These tools create, display, store, transmit, and exchange information. Information and comn1unications technology (ICT) has influenced all aspects of life significantly. Therefore, ICT is a wide subject in the modern age. Modern organizations and different professionals depend heavily on network con1puting and communication technologies. The use of such technologies is increasing mainly in the fields of education, business, management and entertain1nent. In this lesson, we will study the introduction and general use ofATMs, photocopiers, scanners, printers, routers, Wi-Fi devices, television, and set-top box. Science and Technology, Grade 6 19 Activity 2.1 What type of devices of information and communication technology do you u se every day to accmnplish different tasks? Find the application of these devices and fill in the table below: S.N. ICT devices Application in daily life 1 Computer To use the internet and store data. 2 0 0 0 I I 0 I oeo 0 0 0 0 0 eot Ill 1001 I 00111011 1 11 1 1 1 0 0 111110111111 Ill I I I I I I Ill Automatic Teller Machines (ATMs) ATM stan ds for automatic teller mach in e in its full form. It is an electromechanical machine that provides automated banking services. It helps the customer to make their transaction easily without the help of a branch office, representative or teller. Cash can be withdrawn from ATM using a debit card or credit card. ATMs h elp customers conduct transactions by providing fast, easy andautomated services such as cash withdrawals, cash deposits, bill pay1nents and account to account fund transfers etc. Basic parts of ATM Input and output devices are the main parts of an ATM. It makes it convenient for customers to deposit or withdraw cash. A brief description of the input and output devices in an A TM is given below: Fig 2.3ATM. Input devices Card reader: The card reader recognizes the data stored in the magnetic stripe located at th e back of the ATM card. Account details are retrieved by the card reader and sent to the server. Once the card is inserted into the designated slot of the ATM, the card reader allows the cash dispenser to dispense cash to the user based on the instructions received from the server. Keypad The keypad is a standard input device found in most ATMs. It is used 20 Science and Techn ology, Grade 8 to enter the Personal Identification Number (PIN) to authenticate the user and access their accounts. The keypad typically consists of a set of 10 numeric keys (0-9) and several additional function keys such as "cancel", "clear", "enter", and "language". Users are required to enter their PIN on the keypad to complete a transaction. Output devices Speaker: Many ATMs also have an audio systen1 that provides spoken instructions and feedback to users, especially those who are visually in1paired. The audio system inay also provide an audio confirmation of the transaction. Display Screen The display screen is an essential output device found in all ATMs. It provides users with visual information about their transaction, such as the balance in their account, transaction status, and prompts for entering information. Receipt Printer The receipt printer is another critical output device found in ATMs. It prints out a receipt with the details of the transaction, such as the amount withdrawn or deposited, the remaining balance, and the date and time of the transaction. Cash Dispenser A cash dispenser is an important output device of the ATM that dispenses cash to the user at the end of the transaction. The highly sensitive sensors used in the A TM allow the cash dispenser to administer a specified amount of cash according to the user's needs. ATMs perform cash deposits, cash withdrawals, account statements, account balance statements, PIN code changes etc. Precautions to be taken while using ATMs a) ATM cards and PINs should be kept safe and should not be given to anyone. b) The PIN should be changed from time to time. Science and Technology, Grade 6 21 Activity 2.2 Visit the nearby bank ATM location with your parents. Watch how the cash is withdrawn from the ATMs. Try to use ATMs under parental supervision and with their consent. Photocopy Machine A photocopy machine ni.akes the copy of documents. Xerography technology is used in most photocopy machines. For many years, photocopying was informally known as xeroxing because most photocopiers used xerography. Xerography is a dry process. It uses light as an electrostatic charge on a sensitive photoreceptor. A photocopy machine needs light, heat, pressm·e, chemicals and electrostatic charge to function. A photocopier is a machine for making copies of graphic content and is commonly used in business, education, and government sectors. A scanner, printer, computer network, etc. are also connected to modern photocopy machines. Methods of using photocopy machine Here are the general steps to use a photocopy ' ·-.1 machine. Fig 2.4 Photocopy Machine 1. Turn on the machine To use the photocopier, the first step is to make sure that the plug is connected to a nearby pow er outlet or not. Then press the button to switch on the machine. Most photocopiers have the pow er button on the top, but son1e machines may have the switch button on the side. If the machine does not respond when the button is switched on, it 1nay be in sleeping mode. Before going to the next step, make sure that there is enough paper in the paper tray. The paper tray is usually located at the front of the machine. If there isn't enough paper or the tray is empty, we should keep paper in it. 2. Put the paper in the copier: At this stage, the cover (top) of the photocopier should be lifted and 22 Science and Techn ology, Grade 8 the document to be copied should be placed on the glass surface. The docu1nent to be photocopied should be placed in the machine with the content facing down. Guide marks are also included on the glass to align the document so that it is straight and centred. After placing the document, the cover should be closed. 3. Select the paper size and type Most photocopy inachines have settings to adjust the paper size and type. Select the appropriate size and type based on the document you want to photocopy. 4. Adjust the settings Use the control panel of the photocopy machine to adjust the settings, such as the number of copies, the darkness or lightness of the copy, and any other desired features like colour or black and white printing. Many photocopy machines have only black and white mode. 5. Start the photocopy Press the "Start" button to begin the photocopying process. The machine will scan the docun1ent and produce the required number of copies. 6. Collect the copies Once the photocopy is complete, collect the copies from the output tray. Make sure to check the quality of the copies before proceeding. Activity 2.3 Make a photocopy of an image on an A4 size paper and display it to your class. Scanner An input device used to digitize a picture or text printed on paper and store it in a computer is called a scanner. Some photocopiers can scan documents to create soft copies of the originals. A scanner is an input device that digitizes the picture from the required source for photographic prints, posters, magazine pages, computer editing, and display. A scanner works through Optical Character Recognition Science and Technology, Grade 6 23 (OCR) technology. This process is performed by a scanning head and uses one or more sensors to detect letters or images as light or electrical charges. The majority of scanners are flatbed machines with a flat scanning surface. As Fig 2.5 Scanner a result, it can scan extensive content with ease. Generally, scanners are attached to a computer system and use scanning software. It works to resize the photo or picture and modify the image. A hard copy of the scanned image can be printed if a printer is connected to the computer otherwise it can be stored in digital format. These days, a smartphone app can also be used to perform scanning work. Activity Scan a document at school using a smartphone or scanner with the assistance of theteacher and present it in your class. Printer A printer takes electronic data stored on a computer or other device and produces a hard copy. Since the printer prints digitally stored files in a computer or other device, it is also called a hardcopy output device. A printer is the most popular device used to print textual materials and photos among the external devices of the computer Nowadays , there are different types and capacities of printers available in the market for Fig 2.6 Printer different purposes. Some printers only produce plain black and white prints, while others also produce multicoloured prints. Printer speed is measured in Character Per Second (CPS), Line Per Minute (LPM) and PagesPerMinute (PPM). The printing methods may be different in different printers such as dot print, ink-jet print, laser print etc. 24 Science and Techn ology, Grade 8 Common Steps to use a Printer 1. Ensure that the printer is connected and turned on: Make sure that the printer is properly connected to your computer or mobile device and that it is turned on. Check that there is paper in the paper tray and that there is enough ink or toner in the cartridges. 2. Open the document or image to be printed: Open the digital file that you want to print. This can be a document, image, or another type of file. 3. Choose the printer: If you have inultiple printers connected to your device, choose the printer you want to use from the list of available printers. 4. Choose the print settings: Select the desired print settings, such as the number of copies, orientation, paper size, and print quality. Some printers may have additional settings, such as double-sided printing or borderless printing. 5. Preview the print: Before printing, preview the print to ensure that it looks as you intended. You can usually do this by clicking on the "Print Preview" option. 6. Print the document or image : Once you are satisfied with the print preview, click on the "Print" button to start printing. The printer will start printing the document or image based on the settings you selected. 7. Collect the printout: Once the printing is c01nplete, collect the printout from the output tray. Make sure to check the quality of the printout before proceeding. 8. Turn off the printer: When you have finished printing, turn off the printer and disconnect it frmn your device if necessary. Note that the specific steps may vary depending on the inodel of the printer, so it's always a good idea to consult the user manual for detailed instructions. Activity 2.4 Go to the computer labat your school. Make a Word document of your bio-data on a computer and print it with the assistance of your teacher. Observe the printing process while printing documents. Science and Technology, Grade 6 25 A Router A router is a network connecting device that helps to connect different wired or wireless networks. A router helps to send data from one network to another. It works on the principle of IP (Internet Protocol) address. Nowadays DSL and Optical fibre router are more popular in the market. Routers are Fig 2.7 Router inainly of two types; i.e. wired and wireless. Uses of a Router i. A router is used to connect hardware devices and other servers to a network at a remote location. 11. It exchanges data at a higher speed. So, it is used in both wired and wireless communication. ni. Routers are frequently used by internet service providers to transmit data in the form of email, websites, voice, or video files from source to destination. Additionally, it can transmit data across the globe with the aid of the target IP address. iv. Wireless routers can be used in a client-server format that permits sharing of the Internet, video, data, voice, and hardware resources by configuring a Virtual Private Network (VPN). Wi-Fi Wi-Fi is the short form of 'wireless fidelity'. Wi-Fi is a type of wireless networking system. Communication between devices is established through radio waves in Wi-Fi. It allows Wi-Fi-enabled devices to connect to the Internet and exchange infonnation, digital docun1ents , ilnages , movies, etc. Wi-Fi is a popular wireless networking technology. Wi-Fi was invented by NCR Corporation in the Netherlands in Fig 2.8 Wi-Fi 1991. We can exchange information or data between two or more devices by using Wi-Fi. 26 Science and Techn ology, Grade 8 Wi-Fi was developed for computing devices such as computers and laptops, but nowadays it is widely used in electronic devices such as mobile phones, televisions and digital cameras.Wi-Fi is commonly called Wireless Local Area Network (LAN). Wi-Fi technology allows local area networks to operate wirelessly. It is becoming more and more popular for dmnestic and business uses every day. There are three methods for Wi-Fi signal transmission which are as follows: i. Base station network or Ethernet connection: This is the main host network from where the network is connected to the router. It helps to bring the network signal to our house. 11. Access Point or Router: It is a bridge between wired and wireless networks. A Wired Ethernet connection is used in the router to convert wireless connections. It also spreads the signal around in the form of radio waves. 11i. Devices: We use mobile, computer etc. devices with the help of which we use wireless internet. Set-Top Box A set-top box (STB) is a device that receives digital signals , and decodes and displays television channels. A set-top box is a hardware device. The signal received by the set-top box can be a television signal or an internet data signal. The signal can be received via cable, Fig 2 ·9 Set-top Box optical fibre or telephone connection. The set-top box allows the user to view various programs received from the service provider over the Internet. The set-top box converts the television signal into audio-visual content that can be displayed on a monitor, captured and recorded. In the past, set-top boxes were mainly used for cable and satellite television. Nowadays, Internet facilities are also available in the set-top boxes provided by various Internet service providers. Activity 2. 5 Observe the TV set-top box in your home. Make a list of different parts in the set-top box by identifying them. Science and Technology, Grade 6 27 2.2 Introduction of a Search Engine, Website and ISP Search Engine The search engine is a comn1unication program to search the content on the internet.The search engine is a software system that provides necessary details to users from information placed on the Internet. To get information on any topic, we can use a search engine to find a website related to that topic. Refining your content with a search engine is used for search, saving time and allowing for more precise results. Differentiating between official and non-copyrighted content is silnple with a refined search. Even if don't know the address of the website related to the subject are trying to get, can search by just typing a word. Among the search engines used today, the most used is Google. Due to the excessive use of Google search engines, searching for something new or a topic is usually called 'Googling'. Google has provided various services such as emailing, and translating from one language to another through Google Translator along with the search engine Numerous websites publish the information that we need to use the Internet. We may not know the name of that website. In this case, we can get information by typing only the keyword with the help of a search engine. A search engine is a special type of software that is used to search for content ona website. From the huge amount of information available on the Internet, search engine assists us in finding the information we require. Some of the major search engines are: 1. www.google.com 2. www.yahoo.com 3. www.bing.com 4. www.ask.com 5. www.altavista.com Activity 2.6 To find the Curriculum Development Center website, go to any browser's search engine, click the search button, and type in CuITiculum Development Center. Choose the www.moecdc.gov.np link from the list of links to access the educational resotU'ces you require. 28 Science and Techn ology, Grade 8 Website l. Government of N JMI MiNM:ty of fduc.t~. ScMnc and T.chnOIOgy Curriculum Development Centre Homo AOou1 Ut "' Org:intt3Uon " Publla?Jons 0191tM Llbary Do'Nnlood Contaet Ut Ot'hOrs Onh"n-1 Equiva11nca Fig 2.10 A website serves as a hub for the collection of inultiple web pages and the storage of information about an organization. Any government or non-government organization or business person can create a website on the Internet. Nowadays there are many websites on the Internet where various organizations keep their information. The website starts from www. The full form ofwww is the world wide web. The website of any organization or person is not compatible with any other website in the world. So, every organization has a specific website address which is called a Web address or Universal Resource Locator (URL). A website for a curriculum development centre is www.moecdc.gov.np which contains a variety of educational resource materials. A mobile or co1nputer browser, such as Google Chrome, Microsoft Edge, Safari, Mozilla Firefox, etc., is required to access any website. Parts of the Website A website is a collection of web pages hosted on a web server and consists of the following parts; L Webhosting:Web hosting is a service that allows individuals and organizations to make their websites accessible on the internet. A web hosting company provides server space to store website files, which can then be accessed by internet users via a domain name. Science and Technology, Grade 6 29 11. Web address:A web address, also known as a URL (Uniform Resource Locator), is a unique address that identifies a specific website on the internet. A web address typically consists of three parts: Web addresses are used to navigate to specific websites, pages, or resources on the internet using a web browser. 11i. Homepage: The homepage is the first and most important part of a webpage. It appears first when the user visits the website. The home page defines the look of the website and provides links for the user to browsethe desired page of the website. iv. Digital Content: Each web page in a website contains various types of digital content. Good content placed on the webpage makes the website more effective and attractive. v. Navigation Structure: Navigation structure in a website refers to the organization and arrangement of the pages and sections within the site. It helps users easily navigate and find the content they are looking for. Activity 2.7 Go to the search bar of any web browser, type www.moecdc.gov. np, and press the enter key. Homepage with several options will be displayed choose one of them, such as a Textbook, a catalogue of textbooks for various classes will appear. You can choose the textbook of your class and download it. Internet Service Provider (ISP) Internet service provider refers to a company that provides access to the Internet to personal and business customers. These enable customers to search the web, shop online, conduct business as well as connect with family and friends digitally. ISPs provide their clients with a variety of services, including domain and Fig 2. 11 ISP's Services email hosting, and web hosting. 30 Science and Techn ology, Grade 8 To use this service, the customer has to pay a certain amount to the ISP organization as per their package. This amount also varies according to the amount of data used by the customer or the data plan that the customers want to purchase. Internet Service Providers are also known as Internet Access Providers or Online Service Providers. A provider of information services, storage services, Internet network service providers (INSPs), or a combination of all of these, is referred to as an ISP. In the initial phase, internet service was limited to son1e government agencies and some departments of certain universities. Towards the end of the 1980s, technology was developed to provide Internet access to the common people through the World Wide Web. Telenet is the world's first Internet Service Provider (ISP) and started its service in 1974. Mercantile Company first started internet service in 1994 in Nepal. Features of ISP i. ISP provides high-speed internet service. 11. Most ISPs provide e1nail addresses to their customers. 111. Most ISPs protect their customers against problems such as phishing, malware etc. iv. Smne ISPs also provide web hosting services. 2.3 Social Networking Site Fig 2.12 Various Social Networking Sites This era is the era of technology. There is a saying that goes, "Technology is a useful servant but a dangerous master," attributed to historian Christian Lous Lange. Science and Technology, Grade 6 31 Social networking sites are also known as social networks or social inedia. Social media is a collective form of online communication channel dedicated t o com.munity-based interact ion, content sharing and collaboration. While using social media, users have responsibilities which they must fulfil by following the norms of social media. Some examples of social media are Facebook, Messenger, YouTube, Twitter, Instagram, Google Plus, Tiktok, Blog, etc. The number of Facebook and Twitter users in Nepal is increasing day by day. Any social network has its advantages and disadvantages. Social n1edia has numerous advantages if we can use it properly, but there are a variety of drawbacks if we abuse it. Introduction to the Blog A blog is a short version of a weblog. It is an online journal or informational website where an author or group of authors share their thoughts on a personal topic. Although blogs started as personal diaries, there are more than 570 million blogs on the web nowadays. Blogs are becoming widespread not only for personal use but also in economic, political and social fields. Blogs are also considered important in business. The main purpose of a blog in business is to connect the produced content with the customer. Great blogging makes a business more credible. The b log should be updated frequently. Compared to blogs, websites are static in nature. Blogging is the process of equipping a webpage with tools to facilitate the process of writing, postingand sharing content on the Internet. Similarly, a person who runs and controls a blog is called a blogger. Creating Blog Creating a blog is relatively easy and can be done in just a few simple steps. Here is given how to open a blog account: i. Choose a Platform: The first step in creating a blog is to choose a platform. There are nlany free and paid platforms available including WordPress, Bloggerand Squarespace. WordPress is the most popular blogging platforn1, with over 60 million websites using it. n. Choose a D01nain name: A d01nain name is the address of your 32 Science and Techn ology, Grade 8  blog. It should be easy to remember and related to your blog's content. ni. Select a Hosting provider : A hosting provider is a service that stores your blog's content and makes it available to users on the internet. There are ni.any hosting providers available, including Blogger.com, WordPress.com, Bluehost, and SiteGround etc. iv. Choose a theme: A the1ne is the design of your blog. It determines how your blog looks and feels. Most platforms offer a variety of the1nes to choose from, or you can purchase a custom theme from a designer. v. Start writing: Once you have your platform set up, it's time to start writing! Write high-quality, engaging content that is relevant to your audience. You can also add images , videos, and other multimedia to make your blog more engaging. vi. Promote your blog: To attract readers, you'll need to promote your blog. Share your posts on social media, participate in online communities related to your niche, and engage with your readers to build a following. Creating a successful blog takes time and effort, but with the right strategy and dedication, it can be a rewarding experience. Activity 2.8 Open a blog on the school computer or your parents' smartphone with the help of the teacher/parent, then enter any ideas or write a quick article that you prefer. Opportunities for Social Networking Social media has helped to spread information and communication over the world. The use of social media has spread to almost every nation. People froni. villages and cities everywhere are addicted to social media. If used correctly, social media can be a powerful tool in the world of communication. Some of the advantages and disadvantages of social media are briefly described below Science and Technology, Grade 6 33 Benefits of social media a) Strong Medium Social media is not only a place to share personal sorrows and joys, it has also become a platform for intellectual debate. Recently, social media has also emerged as a powerful ineans of the election campaign and agenda-setting. Therefore, nowadays social media has become a powerful means of personal expression. b) Brand Development Users can get information about any business by using social media. This helps businessmen to achieve professional success. It is also found that people involved in various businesses advertise through social media. c) Customer Interaction The positive feedback given by different custo1ners in the business can be an inspiration for other customers, while the negative feedback can point out their weaknesses in the business and guide the way to improve. Activity 2. 9 StaTt up your parent's smartphone or the PC at school which includes several forms of social networking sites. Ch oose YouTube from the list, then enter "NCED Virtual" in the search field and press the Enter key. Virtual class videos of different subjects of different classes appear as shown in the picture. Open and watch the video of the topic you need. Disadvantages of Social Media Every technology is not only a blessing but also a curse. This state1nent applies to social media as well. Recently, many side effects of social media have also been exposed. Along with its popularity, it has created many dangers or risks which are as follows: a) Health problems People who use social media excessively are at risk of becoming victims of mental illness. They often have problems like depression and insomnia. Blue light emitted from mobile or computer screens inhibits the production of the hormone melatonin that controls our 34 Science and Techn ology, Grade 8 body's "body clock". Melatonin acts to make us feel sleepy. But when its production stops, we stay up late. Many types of health problen1s arise if we do not sleep well. h) Fake accounts It is seen that by creating a fake account in the nanie of a person with any name, sending friend requests to more and more people and taking unauthorized advantage of it. Some people use Facebook and Twitter to spread spam and malware. c) Confidential information leak In this , especially, the employees of any company use social media informally to publicize technical information, so that the confidential information of the company gets out. cl) Targeted })hishing attack Targeted phishing attacks are used to steal money or confidential information. Cyberbullying is an example of phishing. Project work Make a Group discussion with friends about the dangers of social media, the precautions to be taken and the benefits of social media. Present the findings on chart paper. 2.4 General Introduction of Cybercrime, Computer Code of Conduct, Cyber Law and Internet Security Cybercrime Fig 2.13 Various Cybercrime-Related Activities Cybercrime is defined as any crime against a person or group that harms someone's reputation or causes physical or niental trauma Science and Technology, Grade 6 35 through electronic means. Cybercrime is also known as computer crime. The use of computers for illegal activity such as theft of intellectual property, identity theft, violation of privacy, etc. falls under cybercrime. In cybercrime, especially banks and financial institutions, government websites or famous people are targeted through the Internet. Cybercrime is considered a serious crime. Most cybercrimes attack individuals, institutions or government information. A Common Form of Cybercrime i. Identity Theft: Identity theft is the misuse of personal inforn1ation to gain unauthorized access to financial services or steal financial assets. 11. Cyber Terrorism: Cyber terrorism is a cybercri1ne committed against any person, group of persons or government to cause serious harm or extort donations. 111. Cyberbullying : Cyberbullying refers to electronic media such as social mediaor using mods to threaten, intimidate, harass, or hu1niliate someoneor any other form of mental torture. iv. Hacking:Hacking or shutting down a website or computer network through unethical meansis called hacking. v. Defa1nation: Every person has the right to speak on the Internet platform. But if someone's statement harms the reputation of any person or organization, then it is considered defamation and it is also considered a type of cybercrime. Apart from those mentioned above, obscene content and abuse spread on the web, harassment and suffering, spreading hatred and inciting terrorism, distributing child pornography, attracting minors to sex, etc. are also cybercrimes. Project work Attacks against bank ATMs, privacy breaches, the dissemination of offensive content online, the spread of unwanted rumors, and other such crimes are some of the major cybercrimes that take place in our society. Create and post posters with messages to discourage these and other occurrences. 36 Science and Techn ology, Grade 8 Computer Code of Conduct Activity 2.10 A list of dos and don'ts when using a computer is provided in the table below. As listed in the table, observe the dos and don'ts you are aware of and complete the table. S. N. Action to be taken Action not to be taken 1. Listening to music , Do notdownload or copy a file watching videos and that is protected by copyright. reading the news. 2. 0 0 I 0 0 I 0 I I I I I 0 I I 0 I I............................... 3. 4. A computer code of conduct, also known as a code of ethics, is a set of guidelines that outlines the ethical and professional standards expected of individuals who use computers and technology. This prevents the user from committing illegal acts such as being cheated or involved in bad deeds. While using Information and Communication Technology (ICT) users, programmers, operators or anyone else must follow the code of computer ethics. One should not steal information, software, data file or any personal or collective record using computers, smartphones, tablets etc. to causeharm to others, spoil them or use computer viruses to do unethical acts. It is the responsibility of all of us to follow the code of computer ethics. The list below, provided in point forn1, includes some computer usage guidelines. a) Respect for Intellectual Property: Users should respect the intellectual property rights of others and not copy, distribute, or use copyrighted materials without permission. b) Security: Users should take appropriate security measures to protect their data and systems from unauthorized access, viruses, and other threats. c) Professionalism: Users should behave professionally w hen using computers and technology, including avoiding offensive or harassing behaviour. Science and Technology, Grade 6 37 d) Accuracy: Users should ensure that the information they provide or publish is accurate and truthful. e) Compliance with laws and regulations: Users shou ld comply with all applicable laws and regulations related to computer and technology use. f) Reporting violations: Users should report any violations of the code of conduct to the appropriate authorities. Concept of Cyber Law Cyberlaw, also known as Internet law or digital law, is the legal framework that governs the use of the Internet, computers, and related technologies. By defending access to information, privacy, communication, intellectual property, and freedom of speech connected to the use of the Internet, websites, email, c01nputers, smartphones, software, and hardware, cyber laws prevent or mitigate the large-scale harm caused by cyber-criminal acts. Cyber laws provide legal protection to people who use the Internet. Understanding cyber law is extremely in1portant for anyone who uses the Internet. Cyber law is also known as the "law of the Internet". Simplycyber law is the legal system to combat computer crime and harassment. It has strict provisions to punish cyber criminals. Cyber laws give legal authority to digital signatures and electronic documents that are then used in electronic banking, shopping and e-c01nn1erce. It creates rules for the construction of a justice system related to computer crime. The Computer Fraud and Abuse Act (CFAA) was enacted in 1986, as an amendment to the first computer fraud law, to address hacking in the USA. The governn1ent of Nepal passed "The Electronic Transaction and Digital Signature Act-Ordinance" popularly known as 11 Cyber Law" on 30th Bhadra 2061 BS (1 5 September2004). The government of Nepal has passed the "Electronic Transactions Act, 2063 (2007)" and "Electronic Transaction Rules, 2064". Major areas of cyber law include computer crimes such as hacking, digital signatures, Internet of Things (IoT) and identity theft. Cyber Act in Nepal With the increasing incidence of cybercrime in Nepal, it has become 38 Science and Techn ology, Grade 8 necessary to make a separate law. "The Electronic Transactions Act, 2063" deals with various offences of cybercrime, the salient features of which are as follows : i. Hacking or destroying any computer system knowingly without authority will be punished with imprisonment up to three years or a fine of two lakh rupees or both. 11. Access to any computer system without authority will be punishable with imprisonment up to three years or a fine of two lakh rupees or both. 111. Knowingly damaging data from computer systems will be punishable with imprisonment of up to three years or a fine of two lakh rupees or both. iv. Five years imprisonment or one lakh for publishing illegal material through electronic means. v. Computer fraud is punishable with imprisonment for two years or a fine of one lakh rupees or both In addition to the above-mentioned Act, "The Act Relating to Children, 2075"prohibits taking any immoral pictures of children. In addition, the publication and distribution of any pictures of children are prohibited. Similarly,"The copyright act, 2059" protects the copyright of ideas including computer programs. It prohibits people from copying, n1odifying or using the original work for their benefit. "The Privacy Act, 2075" places responsibility on public organizations to protect individuals' data. They cannot transfer such data to anyone without the owner's consent. Under this, the law provides that anyone who violates privacy by transferring someone's data without consent will be punished with three years of in1prisonment or a fine of 30,000 rupees or both. All the above-mentioned laws issued by Nepal for cybercrime are still not enough. The country needs to address the loopholes in these laws and encourage their citizens to report incidents of cybercrime. E-commerce, social media and cyber terrorism, among other areas of cyberspace, also require comprehensive legislation. Science and Technology, Grade 6 39 Project work Make a groupby the teacher's directions, and then present a table in each group detailing the offences c01nmitted while using computers and the Internet and the associated penalties through group discussion and reference material research. Internet Security Internet security focuses on the specific threats and vulnerabilities of online access and Internet use. Various security strategies are involved to protect the activities and transactions conducted over the Internet. These strategies are intended to protect users from threats such as hacking into cornputer systems, ernail addresses or websites. Using various software on the Internet, hackers can steal personal data such as bank account infonnation and credit card numbers etc. In today's digital world, many of our daily activities rely on the Internet. Various forms of communication, entertainment, financial and other related activities are completed online. This means that a lot of data and sensitive information is constantly being shared over the Internet. The Internet is often private and secure, but it can also be an insecure ch annel for sharing infonnation. There is a high risk of security by cyber criminals. Internet security is a matter of priority for individuals and official purposes. Data entered into web forms, as well as overall authentication and security of data delivered over Internet Protocol, are all covered by Internet security in general. Internet security is a branch of computer security. It covers internet, browser security, website security and network security. The purpose of Internet security is to find ways to protect against various attacks on the Internet. Risk of Internet security The internet has become an integral part of our daily lives, and while it offers many benefits, there are also risks associated with internet security. Some of the most common risks of internet security include: Malwa.re: Malware is a type of software that is designed to harm or exploit a computer syste1n. Malware can come in many forms, 40 Science and Techn ology, Grade 8 such as viruses, worms, Trojan horses, and spyware. Malware can steal personal information, damage files, and even take control of a computer system. Phishing: Phishing is a type of social engineering attack that involves tricking people into giving away their personal information. Phishing attacks usually come in the form of emails, text messages, or pop-up windows that appear to be fro1n a trusted source. Identity theft: Identity theft is a type of fraud that involves stealing son1eone's personal information, such as their name, date of birth, Social Security number, and credit card information. This information can be used to commit various types of fraud, such as opening credit card accounts or taking out loans in the victim's name. Hacking: Hacking is the process of gaining unauthorized access to a computer system or network. Hackers can steal sensitive information, install malware, and even take control of c01nputer systems. Botnet: Botnets are a significant threat to internet security, as they can be used to carry out large-scale attacks that can disrupt critical services, steal sensitive information, and cause significant financial damage. Protecting against botnets requires a multi-layered approach, including deploying effective security software, keeping software and systems up-to-date, and educating users about safe online behaviour. Measures of Internet Security Internet security requires various measures to properly protect data. Many measures can be taken to improve internet security, and some of the most effective ones include: i. Use strong passwords: Strong passw ords that are complex and difficult to guess can help protect against unauthorized access to online accounts. ii. Enable two-factor authentication: Two-factor authentication adds an extra layer of security to online accounts by requiring a second form of authentication, such as a code sent to a mobile phone. Science and Technology, Grad e 6 41 iii. Keep software up-to-date: Keeping software, including operating systems and applications, up-to-date with the latest security patches can help protect against known vulnerabilities. iv. Use reputable antivirus and security software: Antivirus and security software can help protect against malware and other cyber threats. v. Use a firewall: A firewall can help block unauthorized access to a network or computer. vi. Back up important data: Regularly backing up important data can help ensure that it can be restored in the event of a cyber-attack or data loss. vii. Educate users: Educating users about safe online behaviour, such as avoiding suspicious emails or links, can help reduce the risk of cyber-attacks. 2.5 Introduction of Robotics and Virtual Reality Robotics Robotics is an interdisciplinary branch of cmnputer science and engineering. Robotics involves the design, construction, operation and use of robots. The goal of robotics is to design machines that can help humans. The fields of mechanical engineering, electrical engineering, computer engineering, and rnathematics are integrated by robotics. Robotics develops machines that can assist humans and imitate human actions. Robots can be used to perform hazardous tasks that humans are unable to complete with the aid of programming, such as following orders in space, disposing of explosives, performing a range of tasks in the deep sea, and working securely in areas with radiation threats. Fig 2. 14 Robot Computer programming has given robots the capacity to do tasks automatically. Cornputer programming is simply 42 Science and Techn ology, Grade 8 understood as software. Robots mainly have two parts software and hardware. Hardware is a physical structure that can be shaped by humans and can be physically touched. Son~e robots look like humans, while others look like machines. This computer programming is done by the tasks that they are designed to perform. The robot functions as a robotics program. Robotic process automation (RPA) imitates human action, and intelligent machines can be built using this model. The following list includes the applications for robots as well as sonie of the crucial tasks they carry out are given below: 1. Manufacturing: Robots are widely used in manufacturing processes to automate repetitive and dangerous tasks such as welding, painting, and assembling pieces of machinery. 2. Healt11care: Robots are used in healthcare to assist with surgeries, deliver medications, and provide physical therapy to patients. 3. Agriculture: Robots are used in agriculture to automate tasks such as planting, harvesting, and crop monitoring, which can improve efficiency and productivity. 4. Logistics: Robots are used in logistics to automate tasks such as packing, sorting, and transporting goods, which can reduce costs and increase efficiency. 5. Exploration: Robots are used in space exploration and deep-sea exploration to gather data and samples from environments that are dangerous or difficult for humans to access. 6. Education: Robots are used in education to teach students about robotics and program111ing, and to provide a practical learning expenence. 7. Entertainment: Robots are used in the entertainment industry, such as in theme parks and movies, to provide interactive experiences for audiences. 8. Security: Robots are also used in security to monitor and patrol areas, detect and defuse explosives and other dangerous devices, fire control, rescuing. Science and Technology, Grade 6 43 Vh1ual Reality Virtual reality (VR) refers to a computer-generated imitati on of a three-dimensional environ1nent that can be interacted within a seemingly real or physical way using special electronic equip1nent. Fig 2.15 Application of Virtual Reality This ilnmersive technology creates an artificial environment that simulates a user's ph ysical presence in a virtual world, allowing them to interact with digital objects and spaces as if they were real. Virtual reality technology typically consists of a display screen that is worn over the eyes, providing users with a stereoscopic view of the simulated environment. The display is often coupled with headphones or speakers to provide an immersive audio experience. In addition, motion-tracking sensors can be used to track the movements of the user's head and hands, allowing for natural and spontaneous interaction with the virtual environment. Virtual reality has a wi de range of applications, including entertainment, gaming , education , training, and simul ation. For example , VR can be used to create immersive and interactive gaming experi ences , simulate dangerous or complexreal- Fig 2.16 Application of Virtual world scenarios for training purposes, Reality or provide a virtual tour of a historical site or museum exhibit. Virtual reality can also be used for therapeutic purposes, such as exposure therapy for anxiety disorders or to help treat post-traumatic stress disorder. Overall, virtual reality technology provides a powerful tool for creating immersive and interactive experiences that can be used for a wide range of applications, from entertainment to education and many other different fields. 44 Science and Techn ology, Grade 8 Application of Virtual Reality Real-world situations are modelled by virtual reality technologies. This technology is utilized in several areas, including the military, sports, mental health, and daily living. The following are some exan1ples of how virtual reality is used : 1. VR in the Military Field VR is widely used in the military field. Virtual reality has been utilized by the military of developed nations for training. Virtual reality has been employed in military training to properly mimic hazardous training scenarios for soldiers and to fly in conflict zones, etc. VR technology is also used to treat post-traumatic sh·ess disorder (PTSD). This treatment is also called Virtual Reality Exposure Therapy (VRET). Which is considered indispensable for soldiers returning from battle. 2. VR in the Education Sector VR is also used in the education sector for teaching and learning activities. Using this technology, students can also be taken on virtual field trips such as museums, solar system tours, and the artificial feeling of going back in time to different eras. These days, virtual classroon1s are being used for an increasing number of teaching and learning activities. 3. VR in the Sports Virtual reality technology can be used by coaches and players to train effectively. Players can improve their performance each thne by repeatedly watching and experiencing specific game scenarios. Similarly, this technology is also being used to improve the audience experience of live sports events. Various sports broadcasters have started strea1ning live games through VR and have arranged to sell virtual tickets for live sporting events. It can enable people anywhere in the world to watch any sports event. Additionally, it enables those who aren't able to afford to spend money to enjoy the game by providing a low-cost live broadcast from their area. 4. VR in the field of Mental Health VR technology is used in Virtual Reality Exposure Therapy (VRET) and it is also being used in the treatment of emotional diseases like anxiety and phobia. For example, an anxious patient can meditate Science and Technology, Grade 6 45 using VR to deal with stress sensitivity and increase coping skills. The VR technology can facilitate a safe environment for patients to face the components that they fear, whilst staying in a guarded and secure environment. 5. VR in Medical Training VR technology is used by medical and dental students to practice surgery. This minimizes the risk of any harm. Practicing medicine through VR helps to in1prove the quality of medical training and also reduces the cost of medical training. 6. VR in the Field of Fashion Nowadays, VR is also being used in the field of fashion. VR is used to display various fashion products, as well as to develop shop layouts. Some of the world's most famous brands are adopting VR technology to facilitate the fashion experience and entice consumers through advertising. 7. VR in the Field of Architecture VR applications provide architects with scale as well as information to present their ideas and designs. Virtual reality applications will be advantageous for all types of construction projects, whether they are residential buildings, commercial buildings, or any other kind. This is because they will enable these projects to be visualized in a virtual environment to interpret every aspect of the project, such as safety precautions or reducing any discrepancy from the final design. The uses and capabilities of technology are limitless. In addition to the above-mentioned uses,VR technology is also being used in fields such as research, entertainment health and safety, heritage and archaeology, fine arts, niarketing, music and concerts etc. 2.6 Introduction and Application of Artificial Intelligence and Cloud Computing Artificial Intelligence Artificial Intelligence (AI) refers to the creation of computer programs or machines that can perform tasks that normally require human intelligence, such as understanding natural language, recognizing objects, making decisions, and solving problems. Artificial intelligence 46 Science and Techn ology, Grade 8 is an emerging technology that can act by understanding intelligence and hunrnn abilities through the use of machines. In the beginning, artificial intelligence was considered a technology that can imitate human intelligence, but nowadays it has been developed in many ways. Artificial intelligence has the power to enhance different types of work, connectivity and productivity. The capabilities of AI are expanding rapidly and its areas of application are increasing day by day Fig 2.17 Artificial Intelligence Artificial intelligence (AI) has also had a great impact on scientific inventions. AI can be classified into three main categories based on its capacity: 1. Narrow or Weak AI: This type of AI is designed to perforn1 a specific task, such as speech recognition or image classification. These systems are not capable of doing anything beyond the task they were program1ned to do. 2. General or Strong AI: This type of AI is designed to be as intelligent as a human being and is capable of performing any intellectual task that a human can do. 3. Artificial Superintelligence (A.SI) :This is a theoretical level of AI that would surpass hun1an intelligence in every way and would be capable of solving problems that are cu1Tently beyond human comprehension. Artificial intelligence can perform various tasks similar to human mind functions. It can comprehend human emotion and engage in social interaction in a group setting. An outstanding example of artificial intelligence is found in self-driving cars, generic robots, chatbots etc. Sophia, the first humanoid robot was brought to Nepal in 2018 at the UNDP conference on "Technology for Public Services" and gave a keynote speech on science and technology, anti-corruption, and other topics. Science and Technology, Grade 6 47  Fig 2.18 Application of Al in a different field Application of AI Artificial Intelligence has various applications in today's society. It is becoming essential for today's tin1.e because it can solve complex problems efficiently in multiple industries, such as healthcare, entertainment, finance, education, etc. AI is making our daily life more comfortable and faster. Following are some sectors which have the application of Artificial Intelligence: 1. Al in Astrono1ny: Artificial Intelligence can be very useful to solve complex universe problems. AI technology can help us understand the universe such as how it works and its origin. 2. AI in Healthcare: In the last five to ten years, AI becoming more advantageous for the healthcare industry and going to have a significant in1pact on this field. Healthcare Industries are applying AI to make a better and faster diagnoses than humans. AI can help doctors with diagnoses and can inform them when patients are worsening so that inedical help can reach the patient before anything happens. 3. AI in Gaming:Al can be used for gaming purposes. The AI machines can play strategic games like chess, where the machine needs to think of a large number of possible places. 48 Science and Techn ology, Grade 8 4. AI in Finance:AI and finance industries are the best matches for each other. The finance industry is implementing automation, chatbot, adaptive intelligence, algorithm trading, and machine learning into financial processes. 5. AI in Data Security: The security of data is crucial for every company and cyber-attacks are growing very rapidly in the digital world AI can be used to make your data safer and secure. 6. AI in Social Media: Social Media sites such as Facebook, Twitter, and Snap chat contain billions of user profiles, which need to be stored and managed in a very efficient way. AI can organize and manage massive an~ounts of data. AI can analyze lots of data to identify the latest trends, hashtags, and requirements of different users. 7. AI in Travel & Transport: Al is becoming highly demanding for travel industries. Al is capable of doing various travel-related works such as making travel arrangements to suggesting the hotels, flights, and best routes to the customers. Travel industries are using AI-powered chatbots w hich can make human-like interactions with customers for better and fast response. 8. Al in Robotics: Artificial Intelligence has a re1narkable role in Robotics. Usually, general robots are programmed such that they can perform some repetitive tasks, but with the help of AI, we can create intelligent robots which can perform tasks with their own experiences without pre-programmed. Humanoid Robots are the best examples of AI in robotics, recently intelligent Hunrnnoid robots named Erica and Sophia have been developed which can talk and behave like humans. 9. AI in Agriculture: Agriculture is an area which requires various resources, labour, money, and time for the best result. Now a day's agriculture is becoming digital, and AI is emerging in this field. Agriculture is applying AI in agriculture robotics, crop monitoring and predictive analysis. AI in agriculture can be very helpful for farmers. 10. AI in Education: AI can alsobe used in the educational sector. AI chatbots can communicate with students as teaching assistants. AI in the future can work as a personal virtual tutor for students, which will be accessible easily at any time and any place. Science and Technology, Grade 6 49 Cloud Computing 11 Al & Machine Learning " sccurl yU Cloud Computing Networking containers compute Fig 2. 19 Cloud Computing In the field of information and communication technology (ICT), cloud cmnputing refers to the use of remote servers hosted on the internet to store, manage, and process data and applications, rather than relying on local servers or personal computers. It is the latest technology based on the Internet. Instead of keeping various files on a hard drive or local storage device, cloud-based storage makes it possible to store them in a remote database. As long as an electronic device is within reach of the web, the data and software programs to operate it are accessible through cloud computing. Cloud computing has becmne a popular choice for people due to n1.any reasons like cost savings, growth, speed, efficiency, performance and security. Cloud computing means that data or information stored in the cloud or virtual space can be viewed and used from anywhere. The companies that provide these computing services are called cloud service providers. Cloud computing services can be both public and private. Internet-based public cloud providers charge a fee for their services. On the other hand, private cloud services only provide services to a certain number of people. Generally, we charge for cloud computing services based on usage. Cloud service providers like 50 Science and Techn ology, Grade 8 Datahub, Silver Lining, and Cloud Himalaya are working in Nepal. Advantages of Cloud Computing There are several advantages of cloud computing some of which are described below: 1. Cost-effectiveness: Cloud computing eliminates the need for businesses to purchase and maintain their IT infrastructure, which can be very expensive. Instead, businesses only pay for the computing resources they actually use. 2. Accessibility: Cloud computing allows users to access their data and applications from anywhere in the world, as long as they have an internet connection. 3. Reliability: Cloud computing providers typically have redundant systems and backup measures in place, which nieans that businesses can be confident that their data will always be available. 4. Security: Cloud computing providers often have better security measures in place than many businesses can afford to implement themselves, which means that data is typically more secure in the cloud than it.. is on-premises. Project work Search the internet to learn about using virtual reality in Nepal. Based on your research, create a PowerPoint presentation and present it to your class. Science and Technology, Grade 6 51 Exercise 1. Choose the best alternative: (a) What is the main function of a set-top box (STB)? i. Receiving the digital signal IL Displaying the television channel ni. Decoding IV. All of the above (b) What is the fixed address of the website 1. WWW ll. URL ni. wave browser IV. wave page (c) Which type of cybercrime is related to Intimidation, defamation or any other form of mental degradation by using electronic means or modes such as social media? L Identity Theft IL Cyberbullying iii. Trade Secrets IV. Hacking (d) What is the latest technology that can understand intelligence and human ability through the use of machines? i. Robotics IL Artificial Intelligence ni. Virtual Reality lV. Google Plus (e) In which category do digital signature falls which measures internet security? i. Certification ll. Browser Selection ni. email security IV. antivirus software (f) Which of the following is an advantage of cloud computing? i. Cloud migration.. ll. Global scale ni. IT Governance lV. Unexpected Costs 52 Science and Techn ology, Grade 8 2. Differentiate between: a) Printers and Scanners b) Search Engines and Websites c) Virtual Reality (VR) and Artificial Intelligence d) Computer Code of Conduct and Cyber Law e) Robotic Humans and Humans 3. Answer the following questions: a) What kind of technology is an ATM? Write its important functions. b) Make a list of various parts of a photocopy machine. c) What is a printer? Mention its function in brief. d) What is a search engine? Illustrate the needfor search engines with exan1ples. e) Write the main features of ISP. f) Mention the opportunities and benefits of social media. g) What is cybercrime? What are the forms of cybercrime? h) Mention the dangers of internet security and ways to avoid them. i) What is computer ethics? j) What is Artificial Intelligence? What is the main objective of artificial intelligence? k) What is robotics? Mention some in1portant tasks performed by robots. 1) What is meant by Virtual Reality? Write the various sector in which it is used. m) What is cloud computing? Write down any two services provided by cloud computing. Science and Technology, Grade 6 53  n) Which is device is used to convert hard copy to soft copy? o) What is a collective form of online communication channel dedicated to community-based interaction, content sharing and collaboration? p) What is the act of shutting down or abusing a website or computer network by unethical means? q) What is the name of the software program that makes copies from one computer to another? r) What is the legal framework to combat cybercrime and harassment? s) Write the full form of the following terms. (i) ATM (ii) WWW (iii) URL (iv)Wi-Fi (v) ISP (vi) AI (vii) VR 54 Science and Techn ology, Grade 8  Living Beings and Their Structure Let's observe the given figures and discuss on following questions: Questions: a. According to Fig. 3.1, what may be the fundamental unit of the structure of living beings? b. Can we classify living beings based onthe type and structure of the cells present in their body? c. Is it possible to see all the organisms shown in fig. 3.1 with the naked eye? There are different kinds of plants and animals on earth having microscopic to developed and large body size. Animals have usually a head, trunk, tail and limbs in their body and plants also usually have root, stem, leaves, flowers and fruits with them. Many small and microscopic organisms do not have such distinct organs or parts in their body. However, all the body parts of organisms are c01nposed of very tiny and microscopic units called cells. With the very perfect coordination of the functions and placement of all these cells, different physiological and metabolic activities are continuously undergoing inside their body by which they are being able to survive. Living beings are classified into different groups and subgroups based on their body structure. Science nnd Technology, Grade 8 55 3.1 Cell Let's discuss on the following questions about plant and animal cells: a. Are all the cells found in the bodies of various species similar? b. Do all types of cells perforn1 a similarfunction? The cell is thebasic unit of every life. The body of every organism,whether it is microscopic or gigantic, is composed of one or many cells. All the mechanisms of lifeprocesses like digestion, respiration, reproduction, internal transportation, photosynthesis etc are accomplished inside or by the action of these cells through biochemical reactions and contraction-relaxation motion. Because of these reasons, cells are also called the functional unit of life. Therefore, cells are structural as well as functional units of life. The branch of biology, that deals with the study of the cell is called Cytology. Activity: 3.1 Take a leaf of water hyacinth or any floating plant. Make slices of the petiole of the leaf with a razor blade as thin as possible. Stain the cut slices in safranin for a few minutes and wash them thoroughly with clean water. Select one of the thinnest slice, put it on a clean slide, cover the specilnen (the stained slice) with a drop of glycerin and finally with a coverslip.A cover slip should not have any air bubbles below. Now, our temporary slide of the petiole of the floating plant is ready. Observe the slide under a microscope. What may be these tiny roomsseen in the section? Are they the cells? Discuss the observation in the class. Let's know The cell was first discovered by Robert Hooke in 1665. He used the word 'Cellulae' for the small rooms seen in the thin slice of cork under the microscope developed himself, which meant 'tiny rooms' in Latin. He concluded that slices of the cork were composed of such tin y cellulae or cells. Later on , vari ous experiments and studies by Theodor Sch wann, Mattias Jakob Schleiden, Rudolf Virchow etc concluded that the body of all living organism s is built by th e composition of one or many cells. When this conclusion was forwarded, cells are considered the fu ndamental (structural as well as functional) unit of life. Ruber Hooke (18July1635-3March1703 56 Science and Techn ology, Grade 8 3.1.1 Shape and Size of Cells Observe the given figure and discuss the following questions: ,_, ' Fig 3.2 Different Types of Cells a. What are the different shapes of the cells shown? b. Are these all cells found in the same organism? Cells are of different shapes and sizes. Generally, animal cells are irregular in shape. They may be oval, spherical, rod-like, elongated, cubical