Particle model of matter

Question 1

State the equation with all units for density

Answer 1

Density = mass / volumeDensity - kg/m3mass - kgVolume - m3

Question 2

How can the density of a regular shaped object be found?

Answer 2

Find mass using an electronic balance.Find volume using a ruler to measure the length of each side and then the equation volume = l x l x lUse the density equation Density = mass / volume

Question 3

How can the density of a irregular shaped object be found?

Answer 3

Find mass using an electronic balance.Find volume using a eureka canUse the density equation Density = mass / volume

Question 4

How can the density of a liquid be found?

Answer 4

Find the volume using a measuring cylinderPlace an empty measuring cycling on an electronic balance and record the mass. Add the liquid and record the new mass. calculate the mass of the liquid (new mass - old mass)Use the density equation Density = mass / volume

Question 5

Describe the state changes in melting

Answer 5

Solid to liquid

Question 6

Describe the state changes in freezing

Answer 6

Liquid to solid

Question 7

Describe the state changes in evaporating

Answer 7

Liquid to gas

Question 8

Describe the state changes in condensing

Answer 8

Gas to liquid

Question 9

Describe the state changes in sublimation

Answer 9

Solid to gas (missing out the liquid stage)

Question 10

Define internal energy

Answer 10

Energy is stored inside a system by the particles

Question 11

Sate the equation for internal energy

Answer 11

Internal energy = Kinetic energy + potential energy

Question 12

Why does heating always increase internal energy

Answer 12

Heating will either cause the substance to heat up and its kinetic energy to increase or the substance will change state and the internal energy will increase

Question 13

If a substance is heating up what factors affect the increase in temperature?

Answer 13

The mass of the substanceThe material ( the specific heat capacity)The rate at which energy is supplied

Question 14

Define specific heat capacity

Answer 14

The specific heat capacity of a substance is the amount of energy required to raise the temperature of one kilogram of the substance by one degree Celsius.

Question 15

State the units for specific heat capacity

Answer 15

J/kg °C

Question 16

When a substance changes state why doesn’t the temperate rise?

Answer 16

All the energy is being used to break bonds and increase the internal energy

Question 17

Define latent heat

Answer 17

The specific latent heat of a substance is the amount of energy required to change the state of one kilogram of the substance with no change in temperature.

Question 18

State the difference between the latent heat of fusion and vaperisation

Answer 18

latent heat of Fusion is when a solid changes to a liquidlatent heat of Vaporisation is when a liquid changes to a gas

Question 19

State the units of latent heat

Answer 19

J/kg

Question 20

Describe the motion of gas particles

Answer 20

constant random motion

Question 21

As a gas is heated how does the particle motion change?

Answer 21

Particles move faster as they have more kinetic energy

Question 22

What causes gas pressure

Answer 22

Moving gas particles colliding with a container/object. this pressure will always create a force at a right angle to the container.

Question 23

Explain the relationship between the temperature of a gas and its pressure?

Answer 23

As temperature increase the pressure increases. this is because the particles have more kinetic energy and move faster. This means there are more collisions each second

Question 24

State the units of pressure

Answer 24

Pascals (Pa)

Question 25

If the volume of a container increases what effect will this have on pressure?

Answer 25

As volume increase pressure decreases. It is an inversely proportional relationship. A large volume will mean less collisions per second

Question 26

When work is done on a gas trying to compress it how does this affect the temperature and internal energy

Answer 26

Internal energy increases as temperature increases and particles move faster

Question 27

What is the average kinetic energy of the molecules related to?

Answer 27

The temperature of a gas

Question 28

What happens to kinetic energy if the temperature of a substance is increased?

Answer 28

The total kinetic energy of the particles increases and so the internal energy increased

Question 29

What is latent heat?

Answer 29

The energy transferred to or from a substance when it changes state

Question 30

What happens to the temperature during change of state?

Answer 30

The temperature is constant, so the total kinetic energy of particles does not change

Question 31

What type of energy changes during a change of state

Answer 31

Potential energy so internal energy must increase as well