Unit 3 - Particle model of Matter

Question 1

Equation for Density

Answer 1

Density = Mass / Volume

ρ =m / V

Question 2

Units for:
- Density,
- Mass &
- Volume

Answer 2

1. kg/m^3 or g/cm^3
2. kg or g
3. m^3 or cm^3

Question 3

What can the particle model explain?

Answer 3

1. The different states of Matter
2. Differences in Denisty

Question 4

What are the steps to calculating the density of regular objects?

Answer 4

1. Measure the mass of the object using a balance or scales.

2.Fill a measuring cylinder with enough water to submerse the object.

3. Take a reading of the volume of water in the Measuring Cylinder.
4. Place the object in the Measuring Cylinder and ensure it is submersed.
5. Take a reading of the volume of water + object in the Measuring Cylinder.
6. Subtract the volume of water from the volume of water + object to find the volume of the object.

7.Use the equation ρ=mV
to calculate the density of the irregular object.

Question 5

Density formula
(Mass as Subject)

Answer 5

Mass = Density x Volume

Question 6

Density Formula
(Volume as Subject)

Answer 6

Volume = Mass / Density

Question 7

What is internal energy?

Answer 7

The total kinetic energy and potential energy of all
the particles (atoms and molecules) that make up a system.

Question 7

Changes of state are…

Answer 7

Physical changes which differ from chemical changes because the material recovers its original properties if the change is reversed.

Question 8

Equation for SHC

Answer 8

Change in Thermal energy = Mass x Specific Heat Capacity x Change in Temperature

∆ E = m c ∆ θ

Question 9

Equation for SHC
(Change in Temp. as Subject)

Answer 9

Change in Temp = Thermal energy / (Mass x SHC)

Question 10

Equation for SHC
(SHC as Subject)

Answer 10

SHC = Change in Temp. / (Mass x Thermal energy)

Question 11

Equation for SHC
(Mass as Subject)

Answer 11

Mass = Change in Temp. / (Thermal energy x SHC)

Question 12

Units for:
- SHC,
- Mass,
- Change in Temp. &
- Thermal Energy

Answer 12

1. J/kg°C
2. kg
3. °C
4. J

Question 13

Why doesn’t the internal energy supplied increase the temperature of a substance about to change state?

Answer 13

Its being used to break bonds between atoms

Question 14

What is SHC?

Answer 14

The amount of energy a substance needs to raise the temperature of 1kg of this substance by 1°C

Question 15

What is SLH

Answer 15

The amount of energy a substance needs to change the state of 1kg of this substance by 1°C, with no change in temperature

Question 16

Equation for SLH

Answer 16

Energy needed for a change in state = Mass x SLH

Question 17

Units for:
- SLH,
- Mass
- Energy

Answer 17

1. J/kg
2. kg
3. J

Question 18

What is the specific latent heat of fusion?

Answer 18

Change of state from solid to liquid or liquid to solid

Question 19

What is the specific latent heat of vaporisation?

Answer 19

Change of state from liquid to gas or gas (vapour) to liquid.

Question 20

The molecules of a gas are in constant random motion…

Answer 20

The temperature of the gas is related to the average kinetic energy of the molecules.

Question 21

How is the temprature of gas related to its pressure?

Answer 21

The particles with higher kinetic energy stores move faster, colliding harder and more often with each other and the walls of the container (increasing pressure in a fixed container).

Question 22

Temperature and Pressure are ____ Proportional

Answer 22

Directly

Question 23

Equation for Pressure

Answer 23

Pressure = Force / Area

P = F / A

Question 24

Pressure and Force are ____ Proportional

Answer 24

Directly

Question 25

Pressure and Area are ____ Proportional

Answer 25

Inversely

Question 26

Units for: - Pressure - Force - Area

Answer 26

1. Pa (pascals) 2. N (newtons) 3. m^2 (metres sqaured)

Question 27

Equation for Constant

Answer 27

Constant = Pressure x Volume pV = Constant

Question 28

How does doing work on an enclosed gas leads to an increase?

Answer 28

The increase in the internal energy of the gas (as kinetic energy of the particles) means that the temperature must increase.