The Particle Model Of Matter

Question 1

What do gases do to become a liquid

Answer 1

They condense

Question 2

How does a substance change state

Answer 2

• Energy must be transferred by heating
• during the changes the particles gain energy which is used to overcome forces of attraction between particles (into a liquid and gas) or lose energy which creates forces of attraction between particles (to a liquid and solid)

Question 3

How are the forces overcome

Answer 3

• some during melting

- some during evaporation or boiling

Question 4

Is evaporation or boiling quicker

Answer 4

• evaporation is faster as it can take place below the boiling point of a substance
• whereas boiling happens at the boiling point

Question 5

How can you condense or freeze

Answer 5

• energy must be transferred from a substance to the environment
• during these changes of state the particles lose energy as forces of attraction form between them

Question 6

Limitations of the particle model

Answer 6

• the size and shape of the particles aren’t taken into account
• the space between particles aren’t taken into account
• the forces between particles aren’t taken into account

Question 7

What is a physical change

Answer 7

• no new substances are made

- the change is often easily reversed

Question 8

What is a chemical change

Answer 8

• new substances are made
• the change is not often easily reversed
• they involve chemical reactions

Question 9

What happens in a chemical change

Answer 9

• Particles separate from one another

- they join in different ways to before

Question 10

What changes happen to the particle within a material when it is heated or cooled

Answer 10

• chemical bonds between the particles may form, break or stretch
• the material will heat up or cool down as the particles within it gain or lose speed

Question 11

What is the internal energy

Answer 11

• the total amount of kinetic energy and potential energy of all the particles in the system

Question 12

What happens when energy is given to raise the temperature

Answer 12

• particles speed up and gain kinetic energy

Question 13

What happens to the energy when a substance melts or boils

Answer 13

• it is put in to breaking the bonds that are holding particles together, increasing the pd

Question 14

What is internal energy

Answer 14

• the energy stored in a system by the particles

Question 15

What happens if you heat a solid

Answer 15

You increase the internal energy

Question 16

What is sublimation

Answer 16

When a solid turns directly to a gas

Question 17

What happens to the mass when changes of state take place

Answer 17

• it is always conserved

Question 18

What are changes of state

Answer 18

Physical changes

Question 19

What happens in evaporation

Answer 19

• When a liquid turns to a gas, but only on the surface of a liquid
• only the particles on the surface have enough energy to turn into a gas

Question 20

What is the specific heat capacity

Answer 20

The amount of energy needed to raise the temp of 1kg of a substance to 1 c

Question 21

If the volume of a containers with a gas stays the same what happens to the pressure

Answer 21

• it increases as the temperature increases
• this means thst the gas particles will be travelling faster and will collide with the walls of the container more frequently and with more force

Question 22

What happens to the pressure and the temp increases

Answer 22

The pressure increases meaning that the pressure is directly proportional to temperature

Question 23

What happens to the pressure if the volume is decreased

Answer 23

It increases

Question 24

What is volume compared to pressure

Answer 24

Volume is inversely proportional to pressure

Question 25

What is the temp of a gas related to

Answer 25

The average kinetic energy of the particles