10th Class: Matter and Temperature

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Questions and Answers

During the process of melting, what happens to the temperature of the system?

It remains the same

What is the name of the process where a solid changes directly into a gas?

Sublimation

What happens to the particles in steam?

They gain extra energy

How can the state of matter be changed into another state?

By changing the temperature Signup and view all the answers

What is the SI unit of temperature?

Kelvin Signup and view all the answers

How do you convert a temperature on the Celsius scale to the Kelvin scale?

By adding 273 Signup and view all the answers

What happens to the particles when the pressure is increased on a substance enclosed in a cylinder?

They come closer Signup and view all the answers

What can be inferred about the state of matter?

It can change into another state by changing the temperature Signup and view all the answers

What is a characteristic of a pure substance?

It has the same characteristic properties regardless of its source Signup and view all the answers

Why can soft drink and soil not be considered pure substances?

They are mixtures of different substances Signup and view all the answers

What does the term 'pure' mean to a common person?

Free from adulteration Signup and view all the answers

What is milk an example of?

A mixture of different substances Signup and view all the answers

Why are milk, ghee, and butter not considered pure substances?

Because they are mixtures of different substances Signup and view all the answers

What can be said about the composition of a pure substance?

It is the same throughout Signup and view all the answers

What is the main difference between a pure substance and a mixture?

A mixture contains more than one pure substance Signup and view all the answers

Who is the Professor and Head of the Department of Education in Science and Mathematics at NCERT?

M. Chandra Signup and view all the answers

What is the title of the chapter that starts on page 1 of the textbook?

Matter in Our Surroundings Signup and view all the answers

Why can sugar be considered a pure substance?

It contains only one kind of matter Signup and view all the answers

Who is the Incharge of the Computer Centre at DESM?

Deepak Kapoor Signup and view all the answers

What is the title of the section that starts on page v of the textbook?

Rationalisation of Content in the Textbook Signup and view all the answers

Who is the Principal (Retd.) from Delhi?

R.A. Goel Signup and view all the answers

What is the page number of the chapter 'Is Matter Around Us Pure?'?

2 Signup and view all the answers

Who is the TGT in Science from JNV, Meerut?

Kuldeep Singh Signup and view all the answers

What is the year mentioned in the textbook?

2024-25 Signup and view all the answers

What happens to the particles when a suspension breaks?

They settle down and do not scatter light anymore Signup and view all the answers

What is the mass percentage of the solution in Example 2.1?

12.5% by mass Signup and view all the answers

What is a characteristic of a colloidal solution?

The mixture appears homogeneous but is actually heterogeneous Signup and view all the answers

Why can colloidal particles scatter a beam of visible light?

Due to their small size Signup and view all the answers

What is an example of a colloidal solution?

Milk Signup and view all the answers

What can be said about the particles of a suspension and a colloidal solution?

The particles of a suspension are larger than those of a colloidal solution Signup and view all the answers

What happens to the mixture obtained by group D in activity 2.2?

It becomes a colloid Signup and view all the answers

Why can't we see colloidal particles with naked eyes?

Due to their small size Signup and view all the answers

What is the unit of pressure exerted by a gas?

Pascal Signup and view all the answers

What is the normal atmospheric pressure at sea level?

1 atm Signup and view all the answers

What is the temperature of water in Celsius at 573 K?

300°C Signup and view all the answers

Why does the temperature remain constant during the change of state?

Because of the absorption or release of heat energy Signup and view all the answers

What can be inferred about the effect of temperature, surface area, and wind velocity on evaporation?

All three factors affect evaporation Signup and view all the answers

What is the physical state of water at 250°C?

Gas Signup and view all the answers

What is the method to liquefy atmospheric gases?

Decrease the temperature Signup and view all the answers

What is the conversion of 1 atmosphere to Pascal?

1.01 × 10^5 Pa Signup and view all the answers

What is the primary reason solid carbon dioxide is also known as dry ice?

It gets converted directly into gaseous state on decrease of pressure to 1 atmosphere Signup and view all the answers

What is the effect of increasing pressure on the state of a substance?

It decreases the distance between the particles Signup and view all the answers

What is the process called when a gas changes directly into a solid?

Deposition Signup and view all the answers

What can be inferred about the state of matter from the camphor experiment?

Pressure and temperature determine the state of matter Signup and view all the answers

What is the reason for the difference in various states of matter?

Difference in the distances between the constituent particles Signup and view all the answers

What is the effect of decreasing pressure on solid carbon dioxide?

It changes directly into a gas Signup and view all the answers

What is the primary reason for the change in state of a substance?

Change in the distances between the constituent particles Signup and view all the answers

What can be said about the process of sublimation?

It is a process where a solid changes directly into a gas Signup and view all the answers

What is the primary criterion for a substance to be considered pure?

All the constituent particles are of the same chemical nature and have the same physical properties. Signup and view all the answers

What is the main difference between a mixture and a pure substance?

A mixture consists of two or more pure substances, while a pure substance consists of a single type of particle. Signup and view all the answers

What is the significance of the experiment conducted by Group A and Group B?

It proves that a mixture can have a uniform composition throughout. Signup and view all the answers

What is the term used to describe a mixture that has a uniform composition throughout?

Homogeneous mixture Signup and view all the answers

What is the primary characteristic of a homogeneous mixture?

It has a uniform composition throughout. Signup and view all the answers

What can be said about the composition of a mixture?

It can be fixed or variable, depending on the mixture. Signup and view all the answers

What is the significance of the concept of purity in chemistry?

It helps to distinguish between a mixture and a pure substance. Signup and view all the answers

What can be inferred about the particles of a mixture?

They can be of the same or different chemical natures. Signup and view all the answers

What is the minimum number of particles of potassium permanganate required to colour a large volume of water?

Millions Signup and view all the answers

What is the primary reason why the smell of incense can be detected even at a distance?

The particles of the incense stick are very small Signup and view all the answers

What is the primary reason why the colour of the ink spreads evenly throughout the water in the beaker?

The particles of the ink are very small Signup and view all the answers

What is the effect of repeated dilution on the colour of the solution?

The colour becomes lighter Signup and view all the answers

What can be concluded about the size of the particles of matter from the experiment?

The particles are very small Signup and view all the answers

What is the purpose of adding honey to the second beaker in the experiment?

To compare the diffusion of ink and honey Signup and view all the answers

What is the time required for the colour of the ink to spread evenly throughout the water?

A few days Signup and view all the answers

What is the significance of the experiment with incense and water?

It shows that particles of matter are very small Signup and view all the answers

What is the address of the Dhankal Bus Stop?

Panihati, Kolkata 700 114 Signup and view all the answers

What is the name of the Chief Editor of the Publication?

Shveta Uppal Signup and view all the answers

What is the paper quality used for printing?

80 GSM Signup and view all the answers

What is the location of the SDA Print ‘N’ Pack?

D-19, Sector-B1, Tronica City Industrial Area, Loni, District Ghaziabad Signup and view all the answers

In which state of matter are the forces of attraction between particles maximum?

Solids Signup and view all the answers

What is the year mentioned in the foreword?

2024-25 Signup and view all the answers

What is the arrangement of particles in solids?

Most ordered Signup and view all the answers

What is the recommendation of the National Curriculum Framework (NCF) 2005?

Children's life at school must be linked to their life outside the school Signup and view all the answers

What is the process of changing from solid state directly to gaseous state without going through liquid state?

Sublimation Signup and view all the answers

What is the price of the publication?

155.00 Signup and view all the answers

What is the characteristic of particles in gases?

High kinetic energy and low intermolecular forces Signup and view all the answers

Who is the Head of the Publication Division?

Anup Kumar Rajput Signup and view all the answers

What is the process of changing from gaseous state directly to solid state without going through liquid state?

Deposition Signup and view all the answers

What is the characteristic of boiling?

It is a bulk phenomenon Signup and view all the answers

What happens to the particles during evaporation?

They gain enough energy to overcome the forces of attraction Signup and view all the answers

What is the difference between evaporation and boiling?

Evaporation is a surface phenomenon while boiling is a bulk phenomenon Signup and view all the answers

What is the characteristic of a homogeneous mixture?

Uniform composition Signup and view all the answers

What is an example of a heterogeneous mixture?

Oil and water Signup and view all the answers

What can be inferred about the colour of the solutions obtained by groups A and B?

The colour is different Signup and view all the answers

What is a solution?

A homogeneous mixture of two substances Signup and view all the answers

Why are groups C and D heterogeneous mixtures?

Because they contain physically distinct parts Signup and view all the answers

What can be said about the composition of the solutions obtained by groups A and B?

The composition is variable Signup and view all the answers

What is the difference between groups A and B?

Group A has a variable composition, while group B has a constant composition Signup and view all the answers

What can be said about the samples distributed to each group?

Each group received a different sample Signup and view all the answers

What is the primary reason for the increase in kinetic energy of particles with an increase in temperature?

Particles gain energy and start moving faster Signup and view all the answers

What is the term for the intermixing of particles of two different types of matter on their own?

Diffusion Signup and view all the answers

Which of the following substances do you think the particles are held together with the greatest force?

Iron nail Signup and view all the answers

What happens to the particles of matter when they are heated?

They move faster Signup and view all the answers

What is the reason for the increase in the rate of diffusion with an increase in temperature?

Particles gain energy and move faster Signup and view all the answers

What is the effect of increasing the temperature on the kinetic energy of particles of matter?

It increases Signup and view all the answers

What is the term for the force of attraction between particles of matter?

Intermolecular force Signup and view all the answers

What is the primary reason for the diffusion of particles of different types of matter?

Particles have space between them Signup and view all the answers

What is the key characteristic that distinguishes an element from other forms of matter?

It is a basic form of matter that cannot be broken down into simpler substances by chemical reactions. Signup and view all the answers

Which of the following properties is NOT characteristic of metals?

They are brittle and shatter easily. Signup and view all the answers

What is the primary difference between water and cooking oil?

Water extinguishes fire, while oil burns in air. Signup and view all the answers

Who is credited with establishing an experimentally useful definition of an element?

Antoine Laurent Lavoisier Signup and view all the answers

What is the term for a change in chemical composition that occurs when one substance reacts with another?

Chemical reaction Signup and view all the answers

What is the term for the change in chemical properties of matter that occurs during a chemical reaction?

Chemical change Signup and view all the answers

Which of the following is an example of a chemical change?

Burning of a candle Signup and view all the answers

What is the term for the process of a substance reacting with another to undergo a change in chemical composition?

Chemical reaction Signup and view all the answers

What is the primary reason for the increase in rate of evaporation when the surface area is increased?

More particles are able to break away from the forces of attraction of other particles. Signup and view all the answers

What happens to the particles of a liquid when it changes into vapour?

They gain kinetic energy and break away from the forces of attraction of other particles. Signup and view all the answers

What is the effect of increase in temperature on the rate of evaporation?

More particles are able to break away from the forces of attraction of other particles. Signup and view all the answers

What happens to the rate of evaporation when the humidity of the surrounding air is high?

The rate of evaporation decreases. Signup and view all the answers

What is the reason for water left uncovered to change into vapour slowly?

The particles with higher kinetic energy are able to break away from the forces of attraction of other particles. Signup and view all the answers

What is the effect of spreading clothes out to dry on the rate of evaporation?

The rate of evaporation increases. Signup and view all the answers

What is the reason for the particles in a liquid to always be moving?

The particles always have some kinetic energy. Signup and view all the answers

At a given temperature, what is true about the particles in a gas, liquid, or solid?

There are particles with different amounts of kinetic energy. Signup and view all the answers

What is the primary reason why the fourth group of students was able to break the human chains formed by the other groups?

The force applied by the fourth group was excessive. Signup and view all the answers

What can be inferred about the state of matter of the sugar or salt crystals?

They are solids with fixed shapes. Signup and view all the answers

What is the reason why the sponge can be compressed?

The air is trapped in the minute holes of the sponge. Signup and view all the answers

What is the characteristic of the particles of matter in a solid state?

They are close together and have a fixed shape. Signup and view all the answers

What can be said about the diver who is able to cut through water in a swimming pool?

The diver is able to demonstrate the property of matter that liquids can flow and change shape. Signup and view all the answers

What is the primary reason why cold food has a weaker smell?

The particles of the food are moving slowly. Signup and view all the answers

What is the characteristic of the particles of matter in a gas state?

They are far apart and moving randomly. Signup and view all the answers

What is the primary reason why the three human chains were able to maintain their shape?

The students were able to form a chain-like structure with their fingers. Signup and view all the answers

What is the minimum number of particles of potassium permanganate required to colour a large volume of water?

Millions Signup and view all the answers

What happens when you add a drop of blue or red ink to a beaker of water?

The colour takes hours or days to spread evenly throughout the water Signup and view all the answers

What is the purpose of the experiment with incense sticks?

To demonstrate the spread of smell over a distance Signup and view all the answers

What happens when you add honey to a beaker of water?

The honey takes some time to dissolve and spread evenly throughout the water Signup and view all the answers

What is the significance of the activity with potassium permanganate?

It illustrates that a small amount of substance can affect a large volume of another substance Signup and view all the answers

What can be inferred about the particles of matter from the activities?

They can divide into smaller particles and still be effective Signup and view all the answers

What is the common theme among the activities with incense sticks, ink, honey, and potassium permanganate?

They all show that a small amount of substance can affect a large volume of another substance Signup and view all the answers

What can be said about the particles of potassium permanganate?

They are millions in number in just one crystal Signup and view all the answers

What is the primary goal of the National Policy on Education (1986) in terms of education?

To create a child-centered system of education Signup and view all the answers

What is the purpose of discouraging sharp boundaries between different subject areas?

To encourage interdisciplinary learning Signup and view all the answers

What is the role of school principals and teachers in implementing a child-centered system of education?

To encourage children to reflect on their own learning and pursue imaginative activities Signup and view all the answers

What is the significance of flexibility in the daily time-table in achieving the goals of the National Policy on Education (1986)?

It enables teachers to implement the annual calendar more effectively Signup and view all the answers

What is the impact of treating children as participants in learning rather than receivers of a fixed body of knowledge?

It inculcates creativity and initiative in children Signup and view all the answers

What is the primary reason for restructuring and reorienting knowledge at different stages in the curriculum?

To consider child psychology and the time available for teaching Signup and view all the answers

What is the impact of the current education system on the gap between the school, home, and community?

It widens the gap Signup and view all the answers

What is the significance of inculcating creativity and initiative in children?

It enables children to engage more meaningfully with the information passed on to them Signup and view all the answers

What happens to the temperature of the system during the conversion of ice to water?

It remains constant Signup and view all the answers

What is the term used to describe the heat energy required to change 1 kg of a solid into a liquid at atmospheric pressure at its melting point?

Latent heat of fusion Signup and view all the answers

What happens to the particles in water at 0°C (273 K) compared to particles in ice at the same temperature?

They have more energy Signup and view all the answers

What is the result of supplying heat energy to water particles?

They start moving even faster Signup and view all the answers

What is the state of matter of the substance when it is changing from liquid to gas?

Vapor Signup and view all the answers

What is the term used to describe the heat energy that gets 'hidden' into the contents of the beaker during the conversion of ice to water?

Latent heat Signup and view all the answers

What is the reason for the constant temperature during the conversion of solid to liquid state?

The heat energy is used to overcome the forces of attraction between particles Signup and view all the answers

What is the result of heating the water in the beaker with the glass rod?

The water starts evaporating Signup and view all the answers

What is the only metal that is liquid at room temperature?

Mercury Signup and view all the answers

Which of the following is NOT a characteristic of non-metals?

They are good conductors of heat and electricity Signup and view all the answers

What is the term used to describe elements that have intermediate properties between metals and non-metals?

Metalloids Signup and view all the answers

Which of the following processes is an example of a physical change?

Making a fruit salad with raw fruits Signup and view all the answers

What is the primary reason why some elements cannot be classified as purely metals or non-metals?

They exhibit intermediate properties Signup and view all the answers

What is the term used to describe the process of passing an electric current through a substance?

Electrolysis Signup and view all the answers

Which of the following is an example of a chemical change?

Rusting of an almirah Signup and view all the answers

What is the primary reason why some elements are classified as metals or non-metals based on their properties?

Their chemical reactivity Signup and view all the answers

What is the primary characteristic of a mixture?

It contains more than one substance mixed in any proportion. Signup and view all the answers

What is the term used to describe the major component of a solution?

Solvent Signup and view all the answers

What type of mixture is characterized by particles that are visible to the naked eye?

Suspension Signup and view all the answers

What is the term used to describe a substance that cannot be broken down by chemical reactions into simpler substances?

Element Signup and view all the answers

What is the term used to describe the dispersed phase in a colloid?

Dispersed phase Signup and view all the answers

What is the primary characteristic of a pure substance?

It contains only one substance. Signup and view all the answers

What is the term used to describe a substance composed of two or more different types of elements, chemically combined in a fixed proportion?

Compound Signup and view all the answers

What is the relative arrangement of particles in solids, liquids, and gases?

Ordered in solids, layered in liquids, and random in gases Signup and view all the answers

What happens to the kinetic energy of particles as you move from solids to gases?

It increases Signup and view all the answers

What is the characteristic of the spaces between particles in gases?

Maximum Signup and view all the answers

What is the phenomenon where particles change from the surface of a liquid to the vapour state?

Evaporation Signup and view all the answers

What is the process where a gas changes directly to a solid without going through the liquid state?

Deposition Signup and view all the answers

What is the primary reason for the difference in the states of matter?

Intermolecular forces Signup and view all the answers

Which state of matter has the most ordered arrangement of particles?

Solids Signup and view all the answers

What is the term for the change of solid state directly to gaseous state without going through the liquid state?

Sublimation Signup and view all the answers

What is the main objective of the National Education Policy 2020 in terms of content load?

Reducing the content load and providing opportunities for experiential learning Signup and view all the answers

What is one of the reasons for rationalizing the contents of textbooks across all classes?

To remove irrelevant content in the present context Signup and view all the answers

Who is the Chairman of the Advisory Group for Textbooks in Science and Mathematics?

J.V. Narlikar Signup and view all the answers

What is the role of Anjni Koul in the Textbook Development Committee?

Member Signup and view all the answers

What is the title of the position held by Rupamanjari Ghosh in the Textbook Development Committee?

Chief Advisor Signup and view all the answers

In what year is the present edition of the textbook published?

2024-25 Signup and view all the answers

What is the role of Asfa M.Yasin in the Textbook Development Committee?

Reader Signup and view all the answers

What is the institution where Anuradha Gulati is a TGT?

CRPF Public School, Rohini, Delhi Signup and view all the answers

What is the characteristic of metals that is not true for non-metals?

They are good conductors of heat and electricity Signup and view all the answers

Which of the following is an example of a metalloid?

Boron Signup and view all the answers

What is the process called when a substance breaks down into two or more substances?

Chemical change Signup and view all the answers

What is the characteristic of non-metals that is not true for metals?

They are poor conductors of heat and electricity Signup and view all the answers

What is the result of passing an electric current through water?

Hydrogen and oxygen gases are produced Signup and view all the answers

What is the difference between a mixture and a pure substance?

A mixture has a variable composition, while a pure substance has a fixed composition Signup and view all the answers

Which metal is liquid at room temperature?

Mercury Signup and view all the answers

What is the result of dissolving common salt in water?

A physical change occurs Signup and view all the answers

What is the primary characteristic of a heterogeneous mixture?

The components cannot be separated by filtration Signup and view all the answers

What is the main difference between a sol and a solution?

The size of the particles Signup and view all the answers

What is the purpose of centrifugation in the separation of colloidal particles?

To separate the colloidal particles from the dispersing medium Signup and view all the answers

What is the dispersed phase in a colloidal solution?

The solute-like component or particles in a colloid Signup and view all the answers

What is the characteristic of a colloidal solution that distinguishes it from a suspension?

The size of the particles Signup and view all the answers

What is the purpose of filtration in the separation of mixtures?

To separate the components of a heterogeneous mixture Signup and view all the answers

What is the difference between a homogeneous mixture and a heterogeneous mixture?

The uniform distribution of the components Signup and view all the answers

What is the classification of colloids based on?

The state of the dispersing medium Signup and view all the answers

What is the main characteristic of a solution?

It is a homogeneous mixture of two or more substances. Signup and view all the answers

What is the dispersed phase in a colloid?

The particles that are too small to be seen with the naked eye. Signup and view all the answers

What is the primary difference between a mixture and a pure substance?

The composition of a pure substance is fixed, while a mixture can have varying proportions. Signup and view all the answers

What is the term for the amount of solute present per unit volume or per unit mass of the solution?

Concentration Signup and view all the answers

What is the definition of an element?

A form of matter that cannot be broken down into simpler substances. Signup and view all the answers

What is the characteristic of a suspension?

The particles are visible to the naked eye. Signup and view all the answers

What is the medium in which the particles are distributed in a colloid?

Dispersion medium Signup and view all the answers

What is the characteristic of a compound?

It is a mixture of two or more different types of elements, chemically combined in a fixed proportion. Signup and view all the answers

What is the primary reason for the increase in kinetic energy of particles as temperature rises?

Particles move faster due to increased temperature Signup and view all the answers

What is the term used to describe the intermixing of particles of two different types of matter on their own?

Diffusion Signup and view all the answers

What can be inferred about the force of attraction between particles of matter in a substance?

It depends on the type of substance Signup and view all the answers

What happens to the particles of matter when they are heated?

They move faster and get farther apart Signup and view all the answers

What can be said about the particles of matter in a substance?

They are always in motion Signup and view all the answers

Why do particles of matter attract each other?

Due to their natural tendency to come together Signup and view all the answers

What is the result of the intermixing of particles of two different types of matter?

Formation of a mixture Signup and view all the answers

What is the term used to describe the energy of motion possessed by particles of matter?

Kinetic energy Signup and view all the answers

What is the primary factor that affects the rate of evaporation?

Surface area exposed to the atmosphere Signup and view all the answers

What is the primary reason why wearing cotton clothes in summer helps to keep us cool?

Cotton helps in easy evaporation of sweat from the body Signup and view all the answers

What is the heat energy required to change 1 kg of a liquid to gas at atmospheric pressure at its boiling point?

Latent heat of vaporisation Signup and view all the answers

What is the unit of measurement for the density of a substance?

kilogram per cubic metre (kg/m³) Signup and view all the answers

Why does a desert cooler cool better on a hot dry day?

Due to the low humidity in the air Signup and view all the answers

What is the reason why we can feel the effect of cooling due to evaporation in our daily life?

Due to the high latent heat of vaporisation of water Signup and view all the answers

What is the process called when a liquid changes into a gas?

Evaporation Signup and view all the answers

What is the amount of heat energy required to change 1 kg of solid into liquid at its melting point?

Latent heat of fusion Signup and view all the answers

Why does our palm feel cold when we put some acetone or petrol on it?

Because the latent heat of vaporisation of the liquid is absorbed from our body Signup and view all the answers

Why are we able to sip hot tea or milk faster from a saucer rather than a cup?

Because the saucer has a larger surface area Signup and view all the answers

What is the unit of measurement for the weight of an object?

Newton (N) Signup and view all the answers

What is the effect of evaporation on the temperature of the surroundings?

It decreases the temperature Signup and view all the answers

What is the reason behind the formation of water droplets on the outer surface of a tumbler after a hot sunny day?

Due to the condensation of water vapour in the air Signup and view all the answers

Why does the body temperature remain constant during the process of sweating?

Because the latent heat of vaporisation is absorbed from the body Signup and view all the answers

What is the temperature in Celsius of 293 K?

20°C Signup and view all the answers

What is the primary reason why water kept in an earthen pot (matka) becomes cool during summer?

Due to the evaporation of water from the pot Signup and view all the answers

What is the primary reason for the ordered arrangement of particles in solids?

High forces of attraction between particles Signup and view all the answers

Which of the following statements is true about the changes of state of matter?

Deposition is a phase transition from gas to solid Signup and view all the answers

What is the primary difference between evaporation and boiling?

Evaporation occurs at the surface, while boiling occurs in the bulk Signup and view all the answers

Which of the following is NOT a characteristic of gases?

Partially ordered arrangement of particles Signup and view all the answers

What is the primary reason for the minimum spaces between particles in solids?

High forces of attraction between particles Signup and view all the answers

Which of the following statements is true about the arrangement of particles in liquids?

Layers of particles can slip and slide over each other Signup and view all the answers

What is the primary reason for the inter-convertibility of states of matter?

Change in both temperature and pressure Signup and view all the answers

Which of the following is a characteristic of deposition?

A gas changes directly to a solid Signup and view all the answers

What is the characteristic of a solution that indicates its stability?

Solute particles do not settle down when left undisturbed Signup and view all the answers

What is the formula to express the concentration of a solution in terms of mass by mass percentage?

Mass of solute / Mass of solution × 100 Signup and view all the answers

What is the difference between a suspension and a solution?

A suspension is unstable while a solution is stable Signup and view all the answers

What is the method of separation used for a suspension?

Filtration Signup and view all the answers

What is the formula to express the concentration of a solution in terms of volume by volume percentage?

Volume of solute / Volume of solution × 100 Signup and view all the answers

What can be inferred about the particles of a solution?

They do not settle down when left undisturbed Signup and view all the answers

What is the characteristic of a suspension that indicates its instability?

Solute particles settle down when left undisturbed Signup and view all the answers

What is the difference between mass by mass percentage and mass by volume percentage?

Mass by mass percentage is a concentration term, while mass by volume percentage is a property of a mixture Signup and view all the answers

Study Notes

Matter in Our Surroundings

Matter can be solid, liquid, or gas, and its state can be changed by changing the temperature.
During the process of melting, the temperature remains the same, and the heat energy is used to change the state of matter.
The state of matter can be changed into another state by changing the temperature.
Some substances change directly from solid to gaseous state and vice versa without changing into the liquid state.

Temperature Scales

The Kelvin scale is the SI unit of temperature, where 0°C = 273.15 K.
To convert a temperature on the Celsius scale to the Kelvin scale, add 273 to the given temperature.

Pressure and State of Matter

Increasing or decreasing pressure can change the state of matter.
The unit of pressure is Pascal (Pa), and 1 atmosphere = 1.01 × 10^5 Pa.
Atmospheric pressure at sea level is 1 atmosphere, and is taken as the normal atmospheric pressure.

Questions and Activities

Convert temperatures from the Kelvin scale to the Celsius scale and vice versa.
Observe and record the evaporation process and the effect of temperature, surface area, and wind velocity on evaporation.
Suggest a method to liquefy atmospheric gases.

Is Matter Around Us Pure?

A pure substance has the same characteristic properties throughout and cannot be separated into its chemical constituents by physical process.
A mixture contains more than one pure substance and can be classified into different types based on the nature of the components.
Examples of pure substances include sugar, and examples of mixtures include milk, ghee, butter, salt, spices, mineral water, and juice.

Types of Mixtures

Depending on the nature of the components, mixtures can be classified into different types.
A suspension is a mixture in which the particles settle down, and a colloid is a mixture in which the particles are uniformly spread throughout the solution.

Concentration of Solutions

The concentration of a solution can be calculated by finding the mass percentage of the solute.
Example: A solution contains 40 g of common salt in 320 g of water. The concentration of the solution is 11.11% mass percentage.

Characteristics of Matter

Matter can be divided into smaller and smaller particles, which are still visible even after repeated dilution.
The smell of an incense stick can be detected even at a distance, showing that particles of matter can spread out and mix with the air.

States of Matter

The states of matter are inter-convertible by changing temperature or pressure.
The difference in states of matter is due to the difference in distances between the constituent particles.
The forces of attraction between particles are maximum in solids, intermediate in liquids, and minimum in gases.
The spaces between particles and kinetic energy are minimum in solids, intermediate in liquids, and maximum in gases.
The arrangement of particles is most ordered in solids, intermediate in liquids, and random in gases.

Sublimation and Deposition

Sublimation is the change of solid state directly to gaseous state without going through liquid state.
Deposition is the change of gaseous state directly to solid state without going through liquid state.
Examples of sublimation and deposition are solid carbon dioxide (CO2) and camphor.

Boiling and Evaporation

Boiling is a bulk phenomenon where particles from the bulk of the liquid change into vapor state.
Evaporation is a surface phenomenon where particles from the surface gain enough energy to overcome the forces of attraction and change into vapor state.

Pure Substances and Mixtures

A pure substance consists of a single type of particle and has a uniform chemical nature.
A mixture is constituted by more than one kind of pure form of matter.
Examples of mixtures are sea water, minerals, and soil.
Homogeneous mixtures or solutions have a uniform composition throughout, such as salt dissolved in water and sugar dissolved in water.

Particles of Matter

Particles of matter possess kinetic energy and are continuously moving.
As temperature rises, particles move faster and kinetic energy increases.
Particles of matter intermix on their own, a process called diffusion, which becomes faster with heating.

Attraction between Particles of Matter

Particles of matter attract each other.
The strength of attraction between particles determines the state of matter (solid, liquid, or gas).
In solids, particles are held together with maximum force, while in gases, they are freely moving.

States of Matter

Matter exists in three states: solid, liquid, and gas.
Characteristics of particles of matter vary between these states.

Evaporation

Evaporation is a surface phenomenon that increases with an increase in surface area.
Rate of evaporation increases with an increase in temperature.
Rate of evaporation decreases with an increase in humidity.

Mixtures

A homogeneous mixture has a uniform composition, e.g., copper sulphate solution.
A heterogeneous mixture has a non-uniform composition, e.g., mixtures of sodium chloride and iron filings, salt and sulphur, or oil and water.

Solutions

A solution is a homogeneous mixture of two or more substances.
Solutions can be found in daily life, e.g., lemonade, soda water.

Elements

An element is a basic form of matter that cannot be broken down into simpler substances by chemical reactions.
Elements can be divided into metals, non-metals, and metalloids.
Metals typically have properties such as lustre, conductivity, ductility, and malleability.

Principles of Child-Centered Education

The National Curriculum Framework (NCF) aims to shift from a traditional, book-based learning approach to a child-centered system.
The new syllabi and textbooks are designed to discourage rote learning and promote integration of subjects.
The success of this approach depends on teachers encouraging children to reflect on their learning and pursue creative activities.

Properties of Matter

Matter can be divided into smaller particles, which can still maintain their properties.
A few crystals of potassium permanganate can color a large volume of water, indicating the presence of millions of tiny particles.
The smell of incense can be detected even after repeated dilution, showing that particles can still be active even when dispersed.

Physical Changes

Physical changes involve a change in state, but the particles remain the same.
Examples of physical changes include melting of ice, boiling of water, and dissolving of common salt in water.

Chemical Changes

Chemical changes involve a change in the composition of particles, resulting in a new substance.
Examples of chemical changes include rusting of iron, cutting of trees, and passing of electric current through water.

Metals and Non-Metals

Metals are typically shiny, malleable, and good conductors of heat and electricity.
Examples of metals include gold, silver, copper, and iron.
Non-metals are typically dull, brittle, and poor conductors of heat and electricity.
Examples of non-metals include hydrogen, oxygen, iodine, and carbon.

Mixtures and Solutions

A mixture contains two or more substances mixed in any proportion.
Solutions are homogeneous mixtures of two or more substances, with a major component (solvent) and a minor component (solute).
Suspensions are heterogeneous mixtures with particles visible to the naked eye.
Colloids are heterogeneous mixtures with particle sizes too small to be seen with the naked eye, but big enough to scatter light.

Pure Substances

Pure substances can be either elements or compounds.
Elements are substances that cannot be broken down by chemical reactions into simpler substances.
Compounds are substances composed of two or more different types of elements, chemically combined in a fixed proportion.

National Education Policy 2020

Emphasizes reducing content load and providing opportunities for experiential learning with a creative mindset.
NCERT has undertaken the exercise to rationalize textbooks across all classes, taking into consideration Learning Outcomes developed by NCERT.

Textbook Development Committee

Chairman: J.V. Narlikar, Emeritus Professor
Chief Advisor: Rupamanjari Ghosh, Professor
Members: Various experts in science and mathematics education

States of Matter

Solids: maximum forces of attraction, minimum kinetic energy, most ordered arrangement of particles
Liquids: intermediate forces of attraction, intermediate kinetic energy, particles can slip and slide over each other
Gases: minimum forces of attraction, maximum kinetic energy, particles move randomly
States of matter are inter-convertible by changing temperature or pressure
Sublimation: change of solid state directly to gaseous state without going through liquid state
Deposition: change of gaseous state directly to solid state without going through liquid state
Boiling: bulk phenomenon where particles from the bulk of the liquid change into vapor state
Evaporation: surface phenomenon where particles from the surface gain enough energy to overcome forces of attraction and change into vapor state

Colloids

Heterogeneous mixture with particles too small to be seen with the naked eye
Classified according to the state of the dispersing medium and the dispersed phase
Examples: whipped cream, fog, ink, smoke
Properties: stable, cannot be separated by filtration, require centrifugation to separate colloidal particles
Components: dispersed phase (solute-like component) and dispersion medium

Mixtures and Pure Substances

Mixture: contains more than one substance mixed in any proportion
Solution: homogeneous mixture of two or more substances with a major component (solvent) and a minor component (solute)
Concentration of a solution: amount of solute per unit volume or mass of the solution
Suspension: heterogeneous mixture with particles visible to the naked eye
Pure substances can be elements or compounds
Element: form of matter that cannot be broken down by chemical reactions into simpler substances
Compound: substance composed of two or more different types of elements, chemically combined in a fixed proportion

Particles of Matter

Particles of matter possess kinetic energy, which increases with temperature.
As temperature rises, particles move faster.
Particles of matter intermix on their own, a process called diffusion, which increases with temperature.
Diffusion occurs when particles of two different types of matter get into the spaces between each other.

Attraction Between Particles

Particles of matter attract each other.
Forces of attraction between particles are maximum in solids, intermediate in liquids, and minimum in gases.
Spaces between particles and kinetic energy of particles are minimum in solids, intermediate in liquids, and maximum in gases.

States of Matter

Matter exists in three states: solid, liquid, and gas.
The arrangement of particles is most ordered in solids, intermediate in liquids, and random in gases.
States of matter are inter-convertible by changing temperature or pressure.
Sublimation is the change of solid state directly to gaseous state without going through liquid state.
Deposition is the change of gaseous state directly to solid state without going through liquid state.

Evaporation and Cooling

Evaporation is a surface phenomenon where particles from the surface gain energy to overcome forces of attraction and change into the vapour state.
Evaporation depends on surface area, temperature, humidity, and wind speed.
Evaporation causes cooling due to the absorption of heat energy from the surroundings.
Latent heat of vaporisation is the heat energy required to change 1 kg of a liquid to gas at atmospheric pressure at its boiling point.
Latent heat of fusion is the amount of heat energy required to change 1 kg of solid into liquid at its melting point.

Examples of Evaporation

Sprinkling water on a hot surface to cool it.
Wearing cotton clothes in summer to cool down.
Using a desert cooler to cool the air.
Keeping water in an earthen pot to cool it.
Feeling cold when applying acetone or petrol on the skin.

Measurement Units

Temperature: kelvin (K)
Length: metre (m)
Mass: kilogram (kg)
Weight: newton (N)
Volume: cubic metre (m3)
Density: kilogram per cubic metre (kg m–3)
Pressure: pascal (Pa)

Concentration of a Solution

A solution is stable, with solute particles not settling down when left undisturbed.
Concentration of a solution can be expressed in three ways:
- Mass by mass percentage: (Mass of solute / Mass of solution) × 100
- Mass by volume percentage: (Mass of solute / Volume of solution) × 100
- Volume by volume percentage: (Volume of solute / Volume of solution) × 100

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