Chapter 1 - "Sates of Matter" - Short Questions

"Sates of Matter" - Short Questions :- 

Question 1 (2 marks)

State two differences between solids and gases in terms of particle arrangement and movement.

Answer:

In a solid, particles are closely packed in a fixed arrangement.
In a gas, particles are far apart and move freely in all directions.

Question 2 (3 marks)

Describe the arrangement and motion of particles in a liquid.

Answer:
Particles are close together.
Particles are arranged randomly.
Particles can move past each other.

Question 3 (2 marks)

Explain why gases can be compressed but solids cannot.

Answer:
Gas particles are far apart, so they can be pushed closer together.
Solid particles are tightly packed with little space between them.

Question 4 (3 marks)

Describe what happens to the particles of a solid when it is heated until it melts.

Answer:
Particles gain kinetic energy.
Particles vibrate more vigorously.
Forces of attraction are weakened and particles move past each other.

Question 5 (2 marks)

Name the process that occurs when:
a) A liquid changes into a gas
b) A gas changes into a liquid

Answer:
a) Evaporation or boiling
b) Condensation

Question 6 (3 marks)

Explain evaporation using the kinetic particle theory.

Answer:
Some particles have higher kinetic energy.
These particles escape from the surface of the liquid.
This can happen at any temperature.

Question 7 (2 marks)

State two factors that increase the rate of evaporation.

Answer:
Higher temperature
Larger surface area
(also acceptable: increased air flow, lower humidity)

Question 8 (3 marks)

Describe the changes in energy and particle movement during condensation.

Answer:
Particles lose kinetic energy.
Particles move more slowly.
Particles come closer together to form a liquid.

Question 9 (2 marks)

Explain why diffusion occurs faster in gases than in liquids.

Answer:
Gas particles move faster.
Gas particles are further apart.

Question 10 (3 marks)

A student sprays perfume at one corner of a room. After some time, the smell is detected across the room. Explain this observation.

Answer:
Perfume particles diffuse through the air.
Gas particles move randomly in all directions.
Particles spread from high concentration to low concentration.

Question 11 (3 marks)

A student says, “Liquids cannot be compressed because their particles do not move.”
Explain why this statement is incorrect.

Answer:
Liquid particles do move.
They slide past each other.
Liquids are difficult to compress because particles are close together, not because they do not move.

Question 12 (3 marks)

When a sealed syringe containing air is pushed, resistance is felt.
Explain this observation using particle theory.

Answer:
Air particles are pushed closer together.
Collisions between particles increase.
Increased pressure resists the force applied.

Question 13 (3 marks)

Ice floats on water even though both are the same substance.
Explain why ice floats using particle arrangement.

Answer:
Particles in ice are arranged in a fixed structure.
This structure has spaces between particles.
Ice is less dense than liquid water.

Question 14 (2 marks)

A wet cloth dries faster on a windy day than on a calm day.
Explain why.

Answer:
Wind removes water vapour from the surface.
This allows more evaporation to occur.

Question 15 (4 marks)

A student heats a liquid and observes bubbles forming throughout the liquid.
b) Explain how this process differs from evaporation.

a) Name the process occurring.

Answer:
a) Boiling
b) Occurs at a fixed temperature.
     Happens throughout the liquid.
     Evaporation occurs at any temperature and only at the surface.

Question 16 (3 marks)

Why does the temperature remain constant during melting, even though heat is supplied?

Answer:
Energy is used to overcome forces of attraction.
Not used to increase kinetic energy.
Particle movement changes from vibrating to sliding.

Question 17 (3 marks)

A gas is cooled at constant pressure.
Describe the changes in particle motion and spacing.

Answer:
Particles lose kinetic energy.
Particles move more slowly.
Particles move closer together.

Question 18 (2 marks)

Explain why a balloon shrinks when placed in a freezer.

Answer:
Gas particles lose kinetic energy.
Particles move closer together, reducing volume.

Question 19 (2 marks)

State two differences between solids and liquids in terms of particle arrangement and movement.

Answer:
Solids: particles closely packed in fixed positions.
Liquids: particles close together but free to move/slide.

Question 20  (2 marks)

Explain why gases cab be compressed but liquids cannot

Answer:
Gas particles are far apart so they can be pushed closer together; liquid particles are already close together with very little space.

Question 21 (2 Marks)

Describe what happens to the particles in a solid as it is heated to its melting point.

Answer:
Particles gain kinetic energy, vibrate more strongly, overcome forces holding them in fixed positions, and change to a liquid.

Question 22 (2 Marks)

Define diffusion.

Answer:
The spreading out of particles from an area of higher concentration to an area of lower concentration.

Question 23 (2 Marks)

Why does diffusion occur faster in gases than in liquids?

Answer:
Gas particles move faster and have larger spaces between them, allowing quicker spreading.

Question 24 (2 Marks)

Describe what happens during condensation in terms of particles.

Answer:
Gas particles lose energy, slow down, move closer, and form a liquid as forces of attraction pull them together.

Thank You!

Sana Shariq

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