Chapter 3 - Kinetic particles Theory

Question 1

Why does a Liquid have a fixed volume?

Answer 1

Particles of a liquid are further away from each other than particles of a solid. However, liquid particles are still quite packed closely together. Thus a liquid cannot be compressed.

Question 2

What is the arrangement of particles and distance between them in solid?

Answer 2

The particles are orderly and closely packed.

Question 3

How is the attractive force between particles in solid?

Answer 3

The force is very strong.

Question 4

How high is the kinetic energy of particles in solid?

Answer 4

The energy is very low.

Question 5

What is the motion of the particles in solids?

Answer 5

Vibrate and rotate about in their fixed positions.

Question 6

What is the arrangement of particles and the distance between them in liquids?

Answer 6

The arrangement is disorderly and less closely packed than in a solid.

Question 7

How strong is the attractive forces between particles in liquids?

Answer 7

Strong

Question 8

What is the kinetic energy level of particles in liquid?

Answer 8

Low

Question 9

What is the motion of particles in liquids?

Answer 9

Slide over each other and move freely throughout the liquid.

Question 10

What is the arrangement of particles and the distance between them in gas?

Answer 10

The arrangement is disorderly and very far apart.

Question 11

How strong is the attractive forces between particles in gas?

Answer 11

Very weak

Question 12

What is the kinetic energy level in gases?

Answer 12

High

Question 13

What is the motion of particles in gases?

Answer 13

Move freely at all directions at high speed.

Question 14

What happens when a solid is heated strongly until it melts?

Answer 14

When a solid is strongly heated, the particles absorb heat energy. Heat energy is converted to kinetic energy and the particles start to vibrate faster about in their fixed positions. When the temperature is high enough, the vibrations of the particles become sufficient to OVERCOME the forces of attraction between them. Particles are now no longer in fixed positions and can move freely throughout the liquid.

Question 15

What happens when a liquid is cooled until it freezes?

Answer 15

The particles lose kinetic energy and begin to move more slowly. When the temperature is low enough, the particles no long have enough energy to move around freely and will start settling down into fixed positions. The particles are packed orderly and vibrating about their fixed positions.

Question 16

What happens when a liquid is heated until is boils?

Answer 16

The particles absorb heat energy when heated. Heat energy is converted into kinetic energy and particles start to move faster as the temperature rises. When the temperature is high enough, the particles have enough energy to overcome the forces of attraction holding them together. The particles are now far apart and move in all directions at high speeds.

Question 17

What is the difference between boiling and evaporations? (3 points)

Answer 17

• boiling only occurs at boiling point while evaporation occurs at the temperature BELOW boiling point
• boiling occurs throughout the liquid while evaporation only occurs at the surface of the liquid.
• boiling occurs rapidly while evaporation occurs slowly.

Question 18

What is diffusion?

Answer 18

It is the process by which particles of matter fill a space because of random motion&the movement of particles is always from a region of high concentration to a region of low concentration.

Question 19

What is relative molecular mass and what is affected by it?

Answer 19

It is the mass of a gaseous particle and it affects the speed.

Question 20

What if the gas particles move faster?

Answer 20

It has a lower relative molecular mass.

Question 21

What if the gas particles move slower?

Answer 21

It has a higher relative molecular mass.

Question 22

What is the effect of temperature on the rate of diffusion of gases and liquids? Which is faster?

Answer 22

The higher the temperature, the faster the rate of diffusion. This is because particles gain more kinetic energy as temperature increases. They can move faster and increase the rate of diffusion. Thus, the rate of diffusion in liquids is much slower than that in gases.

Question 23

Why does the temperature remain constant during the cooling process? (E.g. Liquid to solid)

Answer 23

Heat energy given out by the particles of liquid are used to attracted the particles to form a solid. This heat energy is given out to the surroundings. Because the heat gain and loss is the same, A mixture of solid and liquid exist at this stage.

Question 24

Why does Solid have a fixed volume?

Answer 24

Solid cannot be compressed as its particles are already very close to each other.