Science 8 Quarter 3 Module 4 Periodic Table of Elements (PDF)

8 Science Quarter 3 – Module 4: Periodic Table of Elements CO_Q3_Science 8_ Module 4 Science – Grade 8 Alternative Delivery Mode Quarter 3 – Module 4: Periodic Table of Elements First Edition, 2020 Republic Act 8293, section 176 states that: N...

8 Science Quarter 3 – Module 4: Periodic Table of Elements CO_Q3_Science 8_ Module 4 Science – Grade 8 Alternative Delivery Mode Quarter 3 – Module 4: Periodic Table of Elements First Edition, 2020 Republic Act 8293, section 176 states that: No copyright shall subsist in any work of the Government of the Philippines. However, prior approval of the government agency or office wherein the work is created shall be necessary for exploitation of such work for profit. Such agency or office may, among other things, impose as a condition the payment of royalties. Borrowed materials (i.e., songs, stories, poems, pictures, photos, brand names, trademarks, etc.) included in this module are owned by their respective copyright holders. Every effort has been exerted to locate and seek permission to use these materials from their respective copyright owners. The publisher and authors do not represent nor claim ownership over them. Published by the Department of Education Secretary: Leonor Magtolis Briones Undersecretary: Diosdado M. San Antonio Development Team of the Module Writers: Elvin O. Belsondra, Mefrel M. Baquial and Marjorie Y. Junio Editor: Mary Luz B. Advincula-Niere Reviewers: Bernabe L. Linog, Edna E. Trinidad, Jane C. Basul, Kevin Hope Z. Salvaňa, Romeo A. Villarin, Alfonz Lexie John C. Basul, Myra Joy B. Montero and Pamela Lou C. Suazo Illustrator: Rosa Mia L. Pontillo Layout Artist: Edgardo Pamugas III Layout Evaluators: Celeste Faith R. Almanon, Jay S. Ayap Management Team: Francis Cesar B. Bringas Isidro M. Biol, Jr. Maripaz F. Magno Josephine Chonie M. Obseňares Gregoria T. Su Marvilyn C. Francia Jay S. Ayap Nonita C. Patalinghug Printed in the Philippines by ________________________ Department of Education – Caraga Region Office Address: Teacher Development Center J.P. Rosales Avenue, Butuan City, Philippines 8600 Telefax: (085) 342-8207/ (085) 342-5969 E-mail Address: [email protected]  8 Science Quarter 3 – Module 4: Periodic Table of Elements Introductory Message This Self-Learning Module (SLM) is prepared so that you, our dear learners, can continue your studies and learn while at home. Activities, questions, directions, exercises, and discussions are carefully stated for you to understand each lesson. Each SLM is composed of different parts. Each part shall guide you step-by- step as you discover and understand the lesson prepared for you. Pre-tests are provided to measure your prior knowledge on lessons in each SLM. This will tell you if you need to proceed on completing this module or if you need to ask your facilitator or your teacher’s assistance for better understanding of the lesson. At the end of each module, you need to answer the post-test to self-check your learning. Answer keys are provided for each activity and test. We trust that you will be honest in using these. In addition to the material in the main text, Notes to the Teacher are also provided to our facilitators and parents for strategies and reminders on how they can best help you on your home-based learning. Please use this module with care. Do not put unnecessary marks on any part of this SLM. Use a separate sheet of paper in answering the exercises and tests. And read the instructions carefully before performing each task. If you have any questions in using this SLM or any difficulty in answering the tasks in this module, do not hesitate to consult your teacher or facilitator. Thank you. CO_Q3_Science 8_ Module 4  What I Need to Know This module was designed and written with you in mind. It is here to help you master the arrangement of elements, the reactive and nonreactive metals. The scope of this module permits it to be used in many different learning situations. The language used recognizes the diverse vocabulary level of students. The lessons are arranged to follow the standard sequence of the course. But the order in which you read them can be changed to correspond with the textbook you are now using. The module contains:  Lesson 1 - Arrangement of Elements  Lesson 2 - Reactive and nonreactive metals After going through this module, you are expected to: 1. Identify the groups and periods of the elements; 2. Describe metals, nonmetals, and metalloids; 3. Compare the relative reactivity of metals; and 4. Use the Periodic Table of Elements to predict the chemical behavior of an element. (MELC Week 7-8 S8MT-IIIi-j-12) 1 CO_Q3_Science 8_ Module 4  What I Know Directions: Choose the letter of the correct answer. Write your answers on a separate sheet of paper. 1. Which term is used to the vertical columns of the periodic table? A. group B. line C. rows D. table 2. What are Group 1 elements known as? A. Alkali metals B. Transition elements C. Representative elements D. Inner transition elements 3. Which element is found in period 6, group 4? A. Cr B. Hf C. Pb D. Ti 4. Elements in the same group have the same number of ________. A. protons B. neutrons C. electrons D. valence electrons 5. In which period and group is Silver (Ag) located? A. Period 2, Group 1 B. Period 3, Group 8 C. Period 4, Group 2 D. Period 5, Group 11 6. How are elements arranged in the Periodic Table? A. increasing atomic radii B. increasing atomic masses C. decreasing atomic masses D. increasing atomic numbers 2 CO_Q3_Science 8_ Module 4 7. Why do elements of the same group have similar chemical properties? A. They have different atomic masses. B. They have one electron in the outer shell. C. They have different number of electrons in the outermost shell. D. They have the same number of electrons in the outermost shell. 8. In which arrangement of elements will reactivity generally become lesser? A. left to right B. bottom to top C. top to bottom D. both A and B For questions, 9-11, use the list of elements in decreasing order of reactivity as shown in the box. K, Na, Ca, Mg, Zn, Fe, H, Cu 9. Which statement about the reactivity of these metals is correct? A. Zinc is less reactive than Iron. B. Sodium is less reactive than Calcium. C. Copper is more reactive than Potassium. D. Calcium is more reactive than Magnesium. 10. Based on the reactivity series, which metal is the most reactive? A. Copper B. Lithium C. Sodium D. Zinc 11. Which of the following sets of metals is arranged according to increasing reactivity? A. K, Mg, Na, Li B. Mg, Li, Na, K C. Mg, Na, Li, K D. Na, Li, Mg, K 12. Which one of the following metals reacts most vigorously with cold water? A. Copper B. Iron C. Magnesium D. Sodium 13. Which set of substances would allow rusting to take place the fastest? A. Iron, salt and water B. Steel, salt and water C. Steel, salt and weak acid D. Iron, salt and weak acid 3 CO_Q3_Science 8_ Module 4 14. If the metal is more reactive, the metal in the compound replaces the less reactive metal. Based on this, which of the following statements is true? A. The less reactive metal repels the more reactive metal from its compound. B. The more reactive metal bonds with the less reactive metal from its compound. C. The more reactive metal pushes out or displaces the less reactive metal from its compound. D. The less reactive metal pushes out or displaces the more reactive metal from its compound. 15. Which metal is preferred to be used for water pipes? because it is unreactive? A. Copper B. Gold C. Iron D. Potassium 4 CO_Q3_Science 8_ Module 4  Lesson 1 Arrangement of Elements All the known chemical elements are arranged on The Periodic Table of Elements in an informative array. There are already 118 elements discovered as of 2019. These elements are arranged from left to right and from top to bottom in an increasing order of atomic numbers. This lesson will help you find out more about the properties of elements. You will see that majority of them are metals, some are non-metals, and few are metalloids. What’s In Activity 1. Crossword Puzzle Directions: Complete the crossword puzzle below. Write your answers on a separate sheet of paper. 5 CO_Q3_Science 8_ Module 4  Across Down 2. They are elements in Group 16. 1. They are generally poor conductors of 3. A property of metal that is capable of heat and electricity. being hammered into thin sheets without 4. It refers to the brightness that a shiny breaking. surface has. 6. An element that has the properties of 5. It is the name of the group of very reactive metals and nonmetals. nonmetals and often used as 8. It is a series of radioactive metallic disinfectant. elements. 7. It is a physical property that is able to 10. It is the horizontal row of the draw out into a thin wire. Periodic Table of Elements. 9. The column of elements on the periodic table What’s New Activity 2, 4 Pics One Word Directions: Reveal the word by analyzing the given set of pictures and letters. Write your answers on a separate sheet of paper. 1. Illustrated by Rosa Mia L. Pontillo 2. Illustrated by Rosa Mia L. Pontillo 6 CO_Q3_Science 8_ Module 4 3. Illustrated by Rosa Mia L. Pontillo 4. Illustrated by Rosa Mia L. Pontillo 5. Illustrated by Rosa Mia L. Pontillo 7 CO_Q3_Science 8_ Module 4  What is It Arrangment of Elements Figure 1 shows the elements on the modern periodic table which are organized based on similarities of properties of elements. Illustrated by Rosa Mia L. Pontillo Figure 1. The Periodic Table of Elements Figure 2 shows the horizontal rows of the periodic table, called periods. Illustrated by Rosa Mia L. Pontillo Figure 2. Elements in Period 5 8 CO_Q3_Science 8_ Module 4 The vertical columns of the periodic table are called groups or families as illustrated in figure 3. The group number corresponds to the number of electrons in their outermost shell. These outermost electrons are called valence electrons. The elements in group of the periodic table have similar chemical properties. Illustrated by Rosa Mia L. Pontillo Figure 3. Elements in Group 13 9 CO_Q3_Science 8_ Module 4 FEATURES OF GROUPS or FAMILIES OF ELEMENTS Elements from the taller columns which are the Groups 1, 2, and 13 through 18 are called representative elements or main groups of the periodic table. Group 1: Alkali Metals Group 2: Alkaline Earth Metals  very reactive, soft,  second most reactive malleable, and elements ductile  malleable, ductile, and  good conductors good conductors of of heat and heat and electricity electricity but not as soft as  with only one valence Group 1 elements electron  with two valence electrons Illustrated by Rosa Mia L. Pontillo Illustrated by Rosa Mia L. Pontillo Figure 4. Group 1, Figure 5. Group 2. the Alkali Metals Group 13: Boron Group Group 14: Carbon Group  are post-transition  also known as the metals, except for Carbon family, or the Boron which is a tetrels metalloid and  elements in this Nihonium which is a family are the key synthetic chemical importance for element that is semiconductor extremely technology radioactive  with four valence  with three valence electrons electrons Illustrated by Rosa Mia L. Pontillo Illustrated by Rosa Mia L. Pontillo Figure 6. Boron Figure 7. Carbon Group Group 10 CO_Q3_Science 8_ Module 4 Group 15: Nitrogen Group 16: Chalcogens Group  Chalcogen is the  known as Pnictogen new trivial name group recognized  with five valence by the International electrons Union of Pure and Applied Chemistry  widely known as Oxygen group  generally nonmetals  with six valence electrons Illustrated by Rosa Mia L. Pontillo Illustrated by Rosa Mia L. Pontillo Figure 8. Nitrogen Figure 9. The group Chalcogen Family Goup 17: Halogens Group 18: Noble Gases  stable gases  salt former  non-reactive or  exist in all three inert elements states of matter  with eight valence  with seven valence electrons except electrons Helium Illustrated by Rosa Mia L. Pontillo Figure 10. The Illustrated by Rosa Mia L. Pontillo Halogen Family Figure 11. The Noble Gases Family 11 CO_Q3_Science 8_ Module 4 Groups 3-12: Transition Metals  hard (with Mercury as an exception)  malleable, ductile, and good conductors of electricity  with one and/or two valence electrons Illustrated by Rosa Mia L. Pontillo Figure 12. Transition metals Figure 13 shows the lanthanides and actinides series. They are special series of elements but are also part of the transition block. They are also called the inner transition elements. Illustrated by Rosa Mia L. Pontillo Figure 13. Lanthanides and Actinides Series 12 CO_Q3_Science 8_ Module 4  Metals, Nonmetals, and Metalloids Nonmetals Metals s Metalloids Illustrated by Rosa Mia L. Pontillo Figure 14. Location of metals, nonmetals, and metalloids In the above figure, metals are located on the left side of the Periodic Table of Elements. Most of the elements are metals which are solids at room temperature except Mercury. Elements that are found far right of the periodic table are called nonmetals which may be solids, liquids or gases. A stair-step line on the table separates the metals from nonmetals. The elements along this line are called metalloids. Metalloids exhibit the properties of metals and nonmetals. The seven elements commonly regarded as metalloids are silicon, germanium, arsenic, antimony, tellurium, and polonium. Table 1. Summary of Properties of Elements Classification of Elements Properties Metals Lustrous (shiny), malleable, hard, ductile Good conductors of heat and electricity Nonmetals Dull in appearance, brittle Poor conductors of heat and electricity Have some properties of metal but behave chemically like a nonmetal in certain instances Metalloids Some are semiconductors,which means they will insulate and conduct electricity 13 CO_Q3_Science 8_ Module 4  What’s More Activity 3. The Missing Element Directions: Fill in the missing information below by using the Periodic Table of Elements. Write your answers on a separate sheet of paper. Illustrated by Rosa Mia L. Pontillo Identify if Metal (M), Element Period Nonmetal (NM) or Name Symbol Group Number metalloid (Met) Number Boron 13 Al 3 Tin Sn Helium 18 Ne 18 Ca 4 Francium 1 Au 6 14 CO_Q3_Science 8_ Module 4  What I Have Learned Activity 4. Fill me Up! Directions: Fill in the blanks with missing word/s. Write your answers on a separate sheet of paper. Elements within the modern periodic table are organized in the simplest way so that information about the elements and their compounds are easily revealed. The vertical columns of the periodic table are called 1._____________. It identifies the 2._____________ of elements. The horizontal rows of the periodic table, called 3._____________ are numbered from top to bottom. There are 18 groups in the Periodic Table of Elements. Group 1 is named as Alkali Metals, Groups 2 as 4._____________, and Group 16 as 5._____________. Groups 3-12 are called as 6._____________. The lanthanides and actinides are special series of elements but are also part of the transition block. They are also called as inner transition elements. Groups 1, 2, 13-18 are called as representative elements. There are three classifications of elements, namely: metals, 7._____________, and metalloids. The majority of the elements on the left side of the periodic table are 8._____________. The nonmetals are confined to the right side of the table. 9._____________show both properties of metals and nonmetals. The physical properties of metals include luster, and 10._____________. 15 CO_Q3_Science 8_ Module 4  Lesson Reactive and Nonreactive 2 Metals There are more than a hundred chemical elements listed on the Periodic Table. Most of these elements are metals which have also been crucial in the development of human civilization. It is therefore important to know something about them. All metals share many features, and we start by looking at these. But they also vary greatly in how reactive they are to combine with other elements to form compounds. What’s In Activity 5. Choose-It-Out Directions: A. From the box below, choose the elements that are metalloids. Write your answers on a separate sheet of paper. Look for applications of these elements in real life. Argon Antimony Boron Mercury Calcium Zinc Germanium Silicon Selenium Astatine 16 CO_Q3_Science 8_ Module 4 B. Choose the elements that are metals. Write your answers on a separate sheet of paper. Look for applications of these elements in real life. Carbon Oxygen Iron Carbon Magnesium Nickel Silver Chlorine Sulfur Lithium A. Metalloids _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ B. Metals _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ 17 CO_Q3_Science 8_ Module 4  What’s New Activity 6. Check this out Directions: Look at the Periodic Table of Elements below and answer the given questions. Write your answers on a separate sheet of paper. (Source:https://sciencenotes.org/periodic-table-black-white-wallpaper) Questions: 1. In a period, the reactivity of metals decreases from left to right. Arrange the given elements in decreasing order: Fe, K, Ca, and Cu ________________________ 2. In a group, the reactivity of metals increases from top to bottom. Arrange the given elements in increasing order: Na, K, Li, and Rb _________________________ 3. Which element is found in period 6, group 14? __________ 4. In which period and group is Aluminum (Al) is located? ___________ 5. In which period and group is Platinum (Pt) is located? __________ 18 CO_Q3_Science 8_ Module 4  What Is It A reaction does not always happen between a metal and a compound. There is an existing definite order of reactivity among metals and hydrogen according to their ability to displace one another. A less reactive metal cannot replace a more reactive metal; hence no reaction will occur. On the other hand, a more reactive metal can replace a less reactive metal and will produce a reaction. To determine the less or more reactive metals refer to the Activity Series of Metals. The Activity Series of Metals Activity 7. In or Out Directions: Write In if the statement is True and Out if the statement is False. Write your answers on a separate sheet of paper. _____1. Potassium, Sodium, and Lithium are metals belonging to Group 1. In this group, its reactivity increases from top to bottom on the Periodic Table. _____2. Sodium, Magnesium, and Aluminum belong to Period 2. In a period, its reactivity decreases from left to right. _____3. Aluminum is more reactive than Lead. _____4. Silver replaces Iron in Iron (II) chloride. _____5. The more reactive metal displaces the less reactive metal from its compound. 19 CO_Q3_Science 8_ Module 4  What’s More Activity 8. Which is which? Directions: Indicate whether the metal is Reactive or Nonreactive with Hydrogen in Hydrochloric acid (HCl) or water (H2O). Please refer to the Activity Series of Metals. Write your answers on a separate sheet of paper. Example: Li with HCl - Reactive 1. Mg with HCl 6. Na with H2O 2. Ag with HCl 7. Cu with H2O 3. Cu with HCl 8. Sn with H2O 4. Au with HCl 9. Pt with H2O 5. Na with HCl 10. K with H2O 5. Na with HCl Activity 9. Will the reaction take place? Directions: Analyze the given reactants below, Can the highlighted metal in the compound be replaced by the metal reactant? Write YES if a reaction will take place and NO if the reaction will not. Write your answers on a separate sheet of paper. Reactions Reactants (YES/NO) 1. Iron (III) oxide Magnesium 2. Copper (II) sulfate Zinc 3. Potassium Aluminum nitrate 4. Gold Silver chloride 5. Calcium Sodium bromide 20 CO_Q3_Science 8_ Module 4  What I Have Learned Directions: Fill in the blanks with the correct answers. Write your answers on a separate sheet of paper. Metals react differently to other substances. Chemists can list 1._____ according to how quickly they undergo chemical reactions, such as burning or dissolving in acids. The result is called a 2._____ series. Metal at the 3._____ of the series generally reacts more vigorously than those that are 4._____ it in the series. Therefore, a 5._____ reactive metal cannot replace a more reactive metal; hence no 6._____ will occur. However, a more reactive metal can 7._____ a less reactive metal producing a reaction. Using the periodic table of 8._____, one can see a trend in reactivity. In a group, reactivity 9._____ as you go from top to bottom, while in a period, reactivity 10._____ from left to right. 21 CO_Q3_Science 8_ Module 4  What I Can Do Activity 10. Which and Why? Directions: Read the given situation and answer the question that follows. Write your answers on a separate sheet of paper. Mary has a bestfriend named Joan who is celebrating her 15th birthday. Mary wanted to buy Joan a bracelet as a gift. In the gift shop, the saleslady presented Mary with three types of bracelets made of the following: Brass (an alloy of Copper and Zinc), Steel (an alloy of Iron and Carbon), and pure Silver. If you were Mary, which bracelet will you buy for Joan? Why? Scoring Rubrics 3 – Discussions do not have misconceptions; with complete scientific evidence. 2 – Discussions do not completely show scientific evidence. 1 – Discussions do not show complete scientific evidence; with misconceptions. 0 – There is no discussion shown. 22 CO_Q3_Science 8_ Module 4  Assessment Directions: Choose the letter of the correct answer. Write your answers on a separate sheet of paper. 1. Which of the elements does NOT belong to the same period? A. Ag B. Co C. I D. Xe 2. Which of the following belongs to the same family of element Phosphorus? A. Carbon B. Magnesium C. Nitrogen D. Oxygen 3. In what period is Manganese located? A. four B. nine C. seven D. two 4. The following elements belong to the same group EXCEPT? A. Argon B. Calcium C. Helium D. Krypton 5. Which of the following BEST describes metals? A. Metals are dull and brittle. B. Metals are insulators and poor conductors of heat. C. Metals are lustrous, malleable, ductile, and good conductors of heat and electricity. D. Metals are dull, brittle, malleable, ductile, and good conductors of heat and electricity. 6. Which of the following statements are NOT TRUE for metalloids? I. They are all semiconductors. II. They are all good conductors of heat and electricity. III. Some of these elements are Boron, Silicon, and Germanium. IV. They are borderline elements that exhibit both metallic and nonmetallic properties to some extent. A. I and II B. II and III C. I and III D. II and IV 23 CO_Q3_Science 8_ Module 4 7. Which metal will most likely replace Copper in Copper(II) chloride? A. Aluminum C. Platinum B. Iron D. Silver 8. Which metal is found at the bottom of the activity series of metals? A. Copper B. Gold C. Iron D. Platinum 9. Which metal is widely used as jewelry? A. Aluminum B. Gold C. Potassium D. Zinc 10. Which one of the following transition metals reacts the least with water? A. Copper B. Gold C. Platinum D. Silver 11. Which one of the following metals reacts most violently with cold water? A. Aluminum B. Copper C. Lithium D. Zinc 12. Which of the following is arranged according to increasing reactivity? A. Fe, Cu, K, Ca B. Cu, Fe, Ca, K C. Cu, Ca, Fe, K D. Ca, Fe, Cu, K 13. In which arrangement of elements will reactivity generally become greater? A. left to right B. bottom to top C. top to bottom D. both A and C 14. Which sets of metals follows the trend of reactivity in a group? A. K, Li, Na, Rb B. Li, K, Na, Rb C. Li, Na, K, Rb D. Na, Li, K, Rb 15. Sodium, Magnesium, and Aluminum belong to period 2. Which of the following statements is correctly stated? A. Aluminum repels Magnesium from its compound. B. Sodium bonds with Aluminum from its compound. C. Aluminum displaces Sodium from its compound. D. Sodium pushes out Aluminum from its compound. 24 CO_Q3_Science 8_ Module 4  Additional Activities Activity 11. Thinking out of the box Directions: Think about the changes that you have observed around you, particularly those involving metals. Write your answers on a separate sheet of paper. 1. What harmful effects could happen when a metal mixes with acids? __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ 2. What are some ways of preventing metals from corrosion? __________________________________________________________________________________ __________________________________________________________________________________ _________________________________________________________________________________ 25 CO_Q3_Science 8_ Module 4 CO_Q3_Science 8_ Module 4 26 What I Have What’s More Learned Activity 3. Activity 4 Identify if 1. Groups Element Symbol Group Period Metal Name Number Number (M), 2. Families Nonmetal 3. periods (NM) or 4. Alkaline earth metalloid metals (Met) 5. Chalcogens Boron B 13 2 Met 6. Transition metals 7. Nonmetals Aluminum Al 13 3 M 8. Metals 9. Metalloids Tin Sn 14 5 M 10. Conductivity Helium He 18 1 NM Neon Ne 18 2 NM Calcium Ca 2 4 M Francium Fr 1 7 M Gold Au 11 6 M What’s New What’s In Activity 2. Activity 1. What I Know 1.A 1. ELEMENTS ACROSS 2.A 2. FAMILY 2. CHALCOGEN 3.B 3. METALS 3. MALLEABLE 4.D 4. PERIOD 6. METALLOID 5.D 5. GROUP 8. ACTINIDE 6.D 10. PERIOD 7.D 8.D DOWN 9.D 1. NONMETALS 10.D 4. LUSTER 11.A 5. HALOGEN 12.C 7. DUCTILE 13.B 9. GROUP 14.C 15.A Lesson 1 Answer Key CO_Q3_Science 8_ Module 4 27 What I Have Learned 1.metals Assessment What I Can Do 2. reactivity 1. B Activit 10. 3. top 2. C 4. below 3. A I will choose Silver 5. less 4. B because according to 6. reaction 5. C the Activity series of 7. replace 6. A metals, it is the least 8. elements 7. A reactive of the three 9. increases 8. D 10. decreases given metals. 9. B 10. D Additional Activities 11. C Activity 11. 12. B 13. C 1. It will corrode 14. C metals. It will make it 15. D weak. 2. By adding a less reactive metal(alloy). Soaking it in oils/grease. Cover it in paint. What’s More What’s New What’s In Activity 5. Act 8. Activity 6. 1. Reactive 1. K, Ca, Fe, Cu A. Boron 2.Non-reactive 2. Rb, K, Na, Li Germaniu 3. Non-reactive Antimony 4. Non-reactive Silicon 5. Reactive What is It Astatine Activity 9. 1. Yes Activity 7. B. Iron 2. Yes 1. In Magnesium 3. Yes 2. In Silver 4. No 3.In Nickel 5. No 4. Out Lithium 5. In Lesson 2 References Davis Ph. D., Raymond E., H. Clark Metcalfe, John E. Williams, and Castka Joseph E. 2002. Modern Chemistry. Texas: Holt, Rinehart, and Winston. Pia C. Campo, et. al. 2013. Science - Grade 8 Learner's Module. Pasig City: Vibal Publishing House, Inc. “Pixabay.” Accessed May 17, 2020. https://pixabay.com/photos/shopping- supermarket-merchandising-1232944/ sciencenotes.org/periodic-table-black-white-wallpaper 28 CO_Q3_Science 8_ Module 4 For inquiries or feedback, please write or call: Department of Education - Bureau of Learning Resources (DepEd-BLR) Ground Floor, Bonifacio Bldg., DepEd Complex Meralco Avenue, Pasig City, Philippines 1600 Telefax: (632) 8634-1072; 8634-1054; 8631-4985 Email Address: [email protected] * [email protected]