1.
State what is meant by a solid.
[1 mark]
- particles in a regular arrangement, vibrate
JD SCIENCE
Particles and kinetic theory
Indicative marking points. Award marks for equivalent scientific or mathematical wording. Do not issue this sheet with the student worksheet.
2.
State what is meant by a liquid.
[1 mark]
- particles touching, can move past
3.
State what is meant by a gas.
[1 mark]
- particles far apart, move freely
4.
State what is meant by density.
[1 mark]
- mass per unit volume
5.
State what is meant by internal energy.
[1 mark]
- total KE + PE of particles
6.
State what is meant by specific latent heat.
[1 mark]
- energy to change state of 1 kg without a temperature change
7.
State what is meant by gas pressure.
[1 mark]
- force of collisions with the walls
8.
State what is meant by Brownian motion.
[1 mark]
- random movement of smoke / pollen
9.
State what is meant by absolute zero.
[1 mark]
- 0 K = −273°C
10.
State what is meant by a change of state.
[1 mark]
- solid ⇌ liquid ⇌ gas
11.
Owain is asked about a solid in a WJEC Physics paper.
(a) [2 marks]
- fixed shape
(b) [3 marks]
- strong forces
12.
Owain is asked about a liquid in a WJEC Physics paper.
(a) [2 marks]
- fixed volume, flows
(b) [3 marks]
- weaker forces than a solid
13.
Owain is asked about a gas in a WJEC Physics paper.
(a) [2 marks]
- fills the container
(b) [3 marks]
- almost no forces
14.
Owain is asked about density in a WJEC Physics paper.
(a) [2 marks]
- ρ = m/V
(b) [3 marks]
- solids usually denser than gases
15.
Owain is asked about internal energy in a WJEC Physics paper.
(a) [2 marks]
- rises when heated
(b) [3 marks]
- temperature is related to mean KE
16.
Owain is asked about specific latent heat in a WJEC Physics paper.
(a) [2 marks]
- E = mL
(b) [3 marks]
- fusion or vaporisation
17.
Density of 40 g in 10 cm³
[3 marks]
- Final answer: 4 g/cm³
18.
Volume of 1.2 kg with density 400 kg/m³
[3 marks]
- Final answer: 0.003 m³
19.
E = mL. 0.25 kg, L=2.3×10⁶
[3 marks]
- Final answer: 5.75 × 10⁵ J
20.
Convert 27°C to kelvin
[3 marks]
- Final answer: 300 K
21.
A gas is heated from 200 K to 400 K at constant V. What happens to pressure?
[3 marks]
- Final answer: it doubles
22.
Mass of 2.0 m³ of air at 1.2 kg/m³
[3 marks]
- Final answer: 2.4 kg
23.
Owain carries out a WJEC-style required practical linked to particle model of matter. This is a typical WJEC required-practical style question.
(a) [2 marks]
- Independent: the independent variable for this topic
- Dependent: the measured outcome
(b) [2 marks]
- keep all other variables constant
- so the test is fair / only one variable is changed
(c) [2 marks]
- repeat and calculate a mean / use a tighter method
24.
Owain carries out collecting valid data for particle model of matter. This is a typical WJEC required-practical style question.
(a) [2 marks]
- Independent: a chosen factor
- Dependent: a quantitative measurement
(b) [2 marks]
- calibrated instrument
- so the test is fair / only one variable is changed
(c) [2 marks]
- systematic error from zero error
25.
Owain carries out drawing a graph for particle model of matter. This is a typical WJEC required-practical style question.
(a) [2 marks]
- Independent: x-variable
- Dependent: y-variable
(b) [2 marks]
- same scale / same apparatus
- so the test is fair / only one variable is changed
(c) [2 marks]
- not drawing a line of best fit through the trend
26.
Owain carries out evaluating a method about particle model of matter. This is a typical WJEC required-practical style question.
(a) [2 marks]
- Independent: method change
- Dependent: precision / accuracy
(b) [2 marks]
- same sample size
- so the test is fair / only one variable is changed
(c) [2 marks]
- too few repeats
27.
Compare a solid with a liquid.
[4 marks]
- particles in a regular arrangement, vibrate
- particles touching, can move past
- give one linked difference
28.
Compare a liquid with a gas.
[4 marks]
- particles touching, can move past
- particles far apart, move freely
- give one linked difference
29.
Compare a gas with density.
[4 marks]
- particles far apart, move freely
- mass per unit volume
- give one linked difference
30.
Compare density with internal energy.
[4 marks]
- mass per unit volume
- total KE + PE of particles
- give one linked difference
31.
Apply your knowledge of gas pressure to this situation: more frequent if T or N increases
[3 marks]
- more frequent if T or N increases
32.
Apply your knowledge of Brownian motion to this situation: caused by unseen particles colliding
[3 marks]
- caused by unseen particles colliding