Use a simple kinetic theory model to explain the different states of matter (solids, liquids and gases) in terms of the movement and arrangement of particles

Recall and use the equation:

density (kilogram per cubic metre, kg/m³) = mass (kilogram, kg) ÷ volume (cubic metre, m³)

\(\rho = \dfrac{m}{V}\)

Core Practical: Investigate the densities of solid and liquids

Explain the differences in density between the different states of matter in terms of the arrangements of the atoms or molecules

Describe that when substances melt, freeze, evaporate, boil, condense or sublimate mass is conserved and that these physical changes differ from some chemical changes because the material recovers its original properties if the change is reversed

Explain how heating a system will change the energy stored within the system and raise its temperature or produce changes of state

Define the terms specific heat capacity and specific latent heat and explain the differences between them

Use the equation:

change in thermal energy (joule, J) = mass (kilogram, kg) × specific heat capacity (joule per kilogram degree Celsius, J/kg °C) × change in temperature (degree Celsius, °C)

\(\Delta Q = m × c × \Delta \theta\)

Use the equation:

thermal energy for a change of state (joule , J) = mass (kilogram, kg) × specific latent heat (joule per kilogram, J/kg)

\(Q = m × L\)

Explain ways of reducing unwanted energy transfer through thermal insulation

Core Practical: Investigate the properties of water by determining the specific heat capacity of water and obtaining a temperature-time graph for melting ice

Explain the pressure of a gas in terms of the motion of its particles

Explain the effect of changing the temperature of a gas on the velocity of its particles and hence on the pressure produced by a fixed mass of gas at constant volume (qualitative only)

Describe the term absolute zero, −273°C, in terms of the lack of movement of particles

Convert between the kelvin and Celsius scales

Explain that gases can be compressed or expanded by pressure changes

Explain that the pressure of a gas produces a net force at right angles to any surface

Explain the effect of changing the volume of a gas on the rate at which its particles collide with the walls of its container and hence on the pressure produced by a fixed mass of gas at constant temperature

Use the equation:

\(P_1 × V_1 = P_2 × V_2\)

to calculate pressure or volume for gases of fixed mass at constant temperature

Explain why doing work on a gas can increase its temperature, including a bicycle pump