P3 Particles

Question 1

Describe the particles in a solid

Answer 1

 Particles in fixed positions
 Particles in ordered arrangement
 Particles touching
 Particles vibrate
 Particles have very strong forces between them
 Particles have the least energy of any state of matter

Question 2

Describe the particles in a liquid

Answer 2

 Particles free to move over each other
 Particles in a random arrangement
 Particles touching
 Particles have quite strong forces between them
 Particles have more energy than in solids less than gases

Question 3

Describe the particles in a gas

Answer 3

 Particles are free to move in all directions
 Particles in a random arrangement
 Particles are far apart
 Particles have very weak forces between them
 Particles have the most energy of any state of matter

Question 4

Name the change in state
between:
a. Solid to liquid
b. Liquid to solid
c. Liquid to gas
d. Gas to liquid
e. Solid to gas

Answer 4

a. Melting
b. Freezing
c. Evaporation or boiling
d. Condensing
e. Sublimating

Question 5

Describe the difference between evaporating and boiling

Answer 5

Evaporating
Takes place at any temperature 
Takes place at the surface only
Can be speaded up by increasing temp, surface area or air movement
Boiling
Takes place only at the boiling point
Takes place throughout the liquid
Can only be speaded up by increasing energy input

Question 6

Define internal energy

Answer 6

The total energy of the particles, the sum of their potential and kinetic stores

Question 7

Define specific heat capacity.

Answer 7

The energy needed to raise the temperature of 1kg of a substance by 1C.

Question 8

Define specific latent heat

Answer 8

The energy needed to change the state of 1kg of a substance.

Question 9

What is the difference between specific latent heat of fusion and vaporization?

Answer 9

Specific latent heat of fusion is energy needed to change solid to liquid.
Specific latent heat of vaporisation is energy needed to change liquid to gas.

Question 10

What causes pressure in a gas?

Answer 10

Collisions between the particles with each other and the surfaces of a container.

Question 11

Why does the pressure in a gas increase as the temperature increases?

Answer 11

 The average kinetic energy of the particles increases
 So the speed of the particles increases
 So there are more frequent and more forceful collisions with each other and the surface of the container
 Pressure = Force/area so as force increases, pressure increases too

Question 12

Explain the increase in temperature when a gas is compressed.

Answer 12

 You transfer energy when a force does work
 The internal energy of the gas increases when it is compresses
 This increases the kinetic energy stores of the particles
 This increases the temperature of the gas

Question 13

What is Boyle’s law

Answer 13

If the temperature of a gas is constant,
Pressure x Volume = constant
(So pressure x volume before a change equals pressure x volume after the change)

Question 14

What equation links density, mass and volume?

Answer 14

Density = mass/volume

Question 15

Why is the density of a solid greater than the density of a gas?

Answer 15

The particles are tightly packed together in a solid so there are more particles in a given volume.

Question 16

How do you find the volume of a cuboid?

Answer 16

Length x Width x Height

Question 17

Describe the changes taking
place from A to E
look at the word document for image

Answer 17

A. Solid is getting hotter. Increase in internal energy causing the particles to vibrate faster
B. Solid is melting. Increase in internal energy is breaking bonds between the particles.
C. Liquid is getting hotter. Increase in internal energy causing the particles to move faster.
D. Liquid is boiling. Increase in internal energy is breaking bonds between the particles.
E. Gas is getting hotter. Increase in internal energy causing the particles to move faster.