Class 9 Science Matter in our surroundings Fill in the blanks , MCQ , True false and Extra question answers.
Fill in the Blanks
1. Everything in the universe is made up of matter.
2. Matter occupies space and has mass.
3. The ancient Indian concept of matter includes five elements called Panch Tatva.
4. Matter is made up of particles.
5. The particles of matter are very small.
6. The process of mixing of particles of different types of matter is called diffusion.
7. Particles of matter are continuously moving.
8. The force of attraction between particles is strongest in solids.
9. Gases are highly compressible.
10. Solids have a definite shape and volume.
11. Liquids have a definite volume but no definite shape.
12. Gases have neither definite shape nor volume.
13. The process in which a solid changes directly to gas is called sublimation.
14. The temperature at which a solid melts is called its melting point.
Multiple Choice Questions
Particles of matter are:
a) Still
b) Very large
c) Continuously moving
d) Inactive
→ c) Continuously moving
Which state of matter has maximum kinetic energy?
a) Solid
b) Liquid
c) Gas
d) Plasma
→ c) Gas
Matter is classified based on:
a) Volume and mass
b) Physical and chemical properties
c) Shape and texture
d) Color and size
→ b) Physical and chemical properties
The smell of perfume spreads due to:
a) Gravity
b) Conduction
c) Diffusion
d) Convection
→ c) Diffusion
Which of the following has a definite shape and volume?
a) Water
b) Oxygen
c) Iron rod
d) Milk
→ c) Iron rod
Which has minimum space between particles?
a) Solid
b) Liquid
c) Gas
d) Plasma
→ a) Solid
What happens to the particles when a solid is heated?
a) They stop moving
b) They come closer
c) They gain energy and move freely
d) They freeze
→ c) They gain energy and move freely
Conversion of liquid to gas is called:
a) Melting
b) Evaporation
c) Condensation
d) Freezing
→ b) Evaporation
Which of these causes cooling?
a) Melting
b) Freezing
c) Boiling
d) Evaporation
→ d) Evaporation
The temperature at which a liquid boils is called:
a) Freezing point
b) Melting point
c) Boiling point
d) Latent point
→ c) Boiling point
The SI unit of temperature is:
a) Celsius
b) Fahrenheit
c) Kelvin
d) Joule
→ c) Kelvin
Ice at 273 K is more effective in cooling than water at 273 K because:
a) It absorbs more heat
b) It is colder
c) It has latent heat
d) It is more solid
→ c) It has latent heat
Which state of matter has no fixed shape but fixed volume?
a) Solid
b) Liquid
c) Gas
d) Plasma
→ b) Liquid
Which one directly changes from solid to gas?
a) Water
b) Camphor
c) Milk
d) Iron
→ b) Camphor
True/False Statements
1. Matter is made up of continuous blocks. — False
2. Matter occupies space and has mass. — True
3. Solids can be compressed easily. — False
4. Diffusion happens only in gases. — False
5. Particles of matter are always moving. — True
6. Ice is a solid form of water. — True
7. Liquids do not have a definite volume. — False
8. Gases have high compressibility. — True
9. Solids flow like liquids. — False
10. Evaporation causes cooling. — True
11. The melting point of ice is 273.15 K. — True
12. Steam has less energy than water at the same temperature. — False
13. Sublimation is the change from solid to gas without liquid stage. — True
14. Liquids can take the shape of the container they are in. — True
15. The rate of evaporation increases with increase in humidity. — False
Answer the following Questions in Short.
Q: What is the boiling point of water at atmospheric pressure?
A: The boiling point of water at atmospheric pressure is 100°C (or 373 K).
Q: What is sublimation?
A: Sublimation is the process in which a solid changes directly into a gas without passing through the liquid state.
Q: What is evaporation?
A: Evaporation is the process in which a liquid changes into vapour at any temperature below its boiling point.
Q: How do the forces of attraction between particles differ in solids, liquids, and gases?
A: The forces of attraction between particles are maximum in solids, intermediate in liquids, and minimum in gases.
Q: What factors affect the rate of evaporation?
A: The rate of evaporation depends upon the surface area exposed to the atmosphere, the temperature, the humidity, and the wind speed.
Q: What is sublimation?
A: Sublimation is the change of solid state directly to gaseous state without going through liquid state.
Q: What is deposition?
A: Deposition is the change of gaseous state directly to solid state without going through liquid state.
Q: What is matter?
A: Matter is anything that has mass and occupies space. It includes everything in the universe, such as air, water, food, stones, plants, and animals.
Q: What is kinetic energy?
A: Kinetic energy is the energy possessed by particles of matter due to their continuous movement.
Q: How does heating affect diffusion?
A: On heating, diffusion becomes faster.
Q: How do solids and liquids diffuse into liquids?
A: Solids and liquids can diffuse into liquids by getting into the spaces between the particles.
Q: What are the three states of matter?
A: The three states of matter are solid, liquid, and gas.
Q: What is latent heat of vaporization?
A: Latent heat of vaporization is the heat energy required to change 1 kg of a liquid to gas at atmospheric pressure at its boiling point.
Q: What is latent heat of fusion?
A: Latent heat of fusion is the amount of heat energy required to change 1 kg of solid into liquid at its melting point.
Q: How can the state of matter be changed?
A: The state of matter can be changed by changing temperature or pressure.
Q: How does the kinetic energy of particles change with an increase in temperature?
A: As the temperature increases, the kinetic energy of particles also increases, and they move faster.
Q: What is diffusion?
A: Diffusion is the intermixing of particles of two different types of matter on their own by getting into the spaces between the particles.
Answer the following Questions in 4-5 Lines.
Q: What are the two types of classification of matter based on physical properties and chemical nature?
A: The two types of classification of matter based on physical properties and chemical nature are:
Physical classification: based on physical properties like color, texture, and shape.
Chemical classification: based on chemical properties like composition, reactivity, and bonding.
Q: How do the characteristics of particles of matter vary in different states of matter?
A: The characteristics of particles of matter vary in different states of matter. In solids, particles are tightly packed, have a definite shape, distinct boundaries, and fixed volumes. In liquids, particles are less tightly packed, have no fixed shape, but have a fixed volume. In gases, particles are far apart, have no fixed shape, and no fixed volume.
Q: What is the difference between solids and liquids?
A: Solids have a definite shape, and fixed volumes, while liquids have no fixed shape but have a fixed volume. Solids are rigid, while liquids are not rigid and can be called fluid.
Q: Why are gases, especially oxygen and carbon dioxide, essential for the survival of aquatic animals and plants?
A: Gases from the atmosphere, especially oxygen and carbon dioxide, diffuse and dissolve in water and are essential for the survival of aquatic animals and plants.
Q: What is diffusion and how does it happen in different states of matter?
A: Diffusion is the intermixing of particles of two different types of matter on their own. It happens in different states of matter through the random movement of particles. In gases, the particles move about randomly at high speed, allowing for fast diffusion. In liquids, the particles move freely and have greater space between each other compared to solids, allowing for a higher rate of diffusion. In solids, the diffusion rate is lower due to the tightly packed particles.
Q: How do aquatic animals breathe under water?
A: Aquatic animals breathe under water due to the presence of dissolved oxygen in water. The oxygen dissolves in water and is absorbed by the animals through their gills, allowing them to survive underwater.
Q: What are some examples of compressed gases and how are they used?
A: Compressed gases include liquefied petroleum gas (LPG) used for cooking, compressed natural gas (CNG) used as fuel for vehicles, and compressed oxygen used in hospitals. They are compressed to reduce their volume for easier transportation.
Q: How does the property of diffusing differ between gases, liquids, and solids?
A: Gases show the property of diffusing very fast into other gases due to the high speed of particles and large space between them. Liquids have a higher rate of diffusion than solids due to the greater space between particles. In solids, the tightly packed particles result in a lower diffusion rate.
Q: What happens to the particles of a solid when its temperature is increased and it melts into a liquid?
A: When the temperature of a solid is increased, the kinetic energy of its particles also increases. The particles start vibrating with greater speed and the energy supplied by heat overcomes the forces of attraction between them. The particles leave their fixed positions and start moving more freely, resulting in the solid melting and becoming a liquid.
Q: What is the melting point and latent heat of fusion of a solid?
A: The melting point is the minimum temperature at which a solid melts to become a liquid at atmospheric pressure. The melting point of ice is 273.15 K. The latent heat of fusion is the amount of heat energy required to change 1 kg of a solid into a liquid at atmospheric pressure at its melting point. It is the heat energy absorbed by the solid during the process of melting, without showing any rise in temperature.
Q: What is the latent heat of vaporisation?
A: A: The latent heat of vaporisation is the amount of heat energy required to change a substance from liquid to vapour at its boiling point, without a change in temperature.
Q: Why do we wear cotton clothes in summer?
A: We wear cotton clothes in summer because cotton is a good absorber of water, which helps in absorbing sweat and exposing it to the atmosphere for easy evaporation, thus keeping our body cool.
Q: Why do we see water droplets on the outer surface of a glass containing ice-cold water?
A: We see water droplets on the outer surface of a glass containing ice-cold water because the water vapour present in air, on coming in contact with the cold glass of water, loses energy and gets converted to liquid state, which we see as water droplets.
Q: How does the arrangement of particles differ in solids, liquids, and gases?
A: The arrangement of particles is most ordered in solids, in liquids layers of particles can slip and slide over each other, and in gases, there is no order, particles just move about randomly.
Q: What is the difference between boiling and evaporation?
A: Boiling is a bulk phenomenon, where particles from the bulk (whole) of the liquid change into vapor state, while evaporation is a surface phenomenon, where particles from the surface gain enough energy to overcome the forces of attraction present in the liquid and change into the vapor state.
