Particle Model Of Matter

Question 1

Describe the particles of a liquid in terms of their energy and movement

Answer 1

Particles are held to close together but can move past each other they form irregular arrangements the particles move randomly at low speeds

Question 2

What is density a measure of

Answer 2

Density is a measure of the amount of mass

Question 3

How does a cooling system affect its internal energy

Answer 3

A cooling system decreases its internal energy

Question 4

What is specific latent heat of vaporisation

Answer 4

The specific latent heat of vaporisation of a substance is the amount of energy needed to change 1Kg of that substance from a liquid to gas

Question 5

What are the units of specific latent heat

Answer 5

J/Kg

Question 6

What are three states of matter

Answer 6

Solid liquid gas

Question 7

For each state of matter describe the arrangement and movement of the particles

Answer 7

Solid- regular arrangement very low energy particles vibrate on the spot
Liquid- irregular arrangement particles move past each other at low speeds
Gas- random arrangement high energy particles move randomly

Question 8

What is formula for density

Answer 8

Mass➗volume

Question 9

Give an example of the possible units for density

Answer 9

Kg/m3

Question 10

What happens to the particles of a substance when that substance is heated

Answer 10

They gain kinetic energy and the particles move faster and they change state

Question 11

Name the 6 changes of state

Answer 11

• freezing
• boiling
• evaporating
• condensing
• melting
• sublimating

Question 12

Is the change of state a physical or chemical change

Answer 12

Physical

Question 13

True or false mass stays the same when a substance changes state and why

Answer 13

True because mass is conserved

Question 14

Explain the cause of the flat sections on a graph of temperature against time for a substance being heated

Answer 14

It’s when energy is being transferred for a substance to change state

Question 15

Define specific latent heat

Answer 15

The amount of energy needed to change 1 kg of a substance from one state of matter to another without changing its temperature

Question 16

What is meant by the term specific heat of fusion

Answer 16

Changing from a solid to liquid or melting or freezing

Question 17

Explain how a gas in a sealed container exerts pressure on the walls of the container

Answer 17

Gas particles move at high speeds and bang into the walls of the container so when they bang into it they exert a force on it.
In a sealed container the outward gas pressure is the total force exerted by all the particles in the gas on a unit area of the container walls

Question 18

A sample of gas is heated in a container with a fixed volume what happens to the pressure of the gas as it’s heated

Answer 18

• as the particles are travelling quicker it means they hit the sides of the container more often in a given amount of time
• each particle has a larger momentum which means they exert a larger force when they collide with the container