Particle Model of Matter

Question 1

1, 000, 000 cm^3 = how many m^3?

Answer 1

1 m^3

Question 2

what is the density of pure water?

Answer 2

1000kg/m^3

Question 3

what is the effect of heating on particles?

Answer 3

raises average energy of each particle

Question 4

why does temperature stay the same until state change process is complete?

Answer 4

energy is used to break/weaken forces of attraction not increase temp

Question 5

what is latent heat?

Answer 5

the energy transferred to a substance when it changes state

Question 6

what is the specific latent heat of fusion?

Answer 6

energy required to turn 1kg of a solid into a liquid, without changing temp

Question 7

what is the specific latent heat of vaporisation?

Answer 7

energy required to turn 1kg of a liquid into a gas, without changing temp

Question 8

how does a gas create pressure?

Answer 8

• particles in a gas move quickly and collide with the walls of the container and each other.
• As they collide with the container walls they exert a force - the force from each particle combined causes pressure that the gas exerts.

Question 9

what happens when you increase temperature in a gas?

Answer 9

• particles move faster as they have more kinetic energy
• collisions are more frequent and harder, so pressure increases

Question 10

what happens when you reduce the volume of a gas?

Answer 10

• same number of gas particles are confined to a smaller space
• collide with container walls more often - pressure increases

Question 11

what is the melting point AKA?

Answer 11

freezing point

Question 12

what is the boiling point AKA?

Answer 12

condensation point

Question 13

what is the difference between boiling and evaporating?

Answer 13

• boiling occurs throughout the liquid and takes place only at BP of liquid; as particles gain more energy, they move more so the bonds between them break and turn into gas.
• evaporating occurs only at liquid surface and takes place at any temperature below boiling and above freezing.

Question 14

describe the behaviour of particles in solids

Answer 14

• forces of attraction: strong
• vibrate around a fixed point
• regular lattice
• little energy
• highest density
• fixed volume and shape

Question 15

describe the behaviour of particles in liquids

Answer 15

• forces of attraction: weaker than solid, stronger than gas
• close together, touching but can move past
• irregular arrangement
• more energy - move randomly at low speeds
• less dense than solids
• fixed volume, variable shape

Question 16

describe the behaviour of particles in gases

Answer 16

• forces of attraction: weak
• free movement
• irregular arrangement
• lots of energy - particles move at different speeds as they have different amounts of kinetic energy
• very low density
• no fixed volume or shape

Question 17

A student only measured the volume of each object once. The volume measurements cannot be used to show that the method to measure volume gives precise readings. Give the reason why.

Answer 17

repeat readings (of volume) need taking of each object to show that the readings are close together

Question 18

what is a change of state defined as?

Answer 18

a physical change that alters the internal energy but not the temperature or mass

Question 19

describe the motion of particles in a gas

Answer 19

constant random motion