Thermal Physics

You will be able to

• Describe the arrangement, separation and motion of particles in solids, liquids and gases.
• Explain that the temperature of a substance is related to the average kinetic energy of its particles.
• Explain Brownian motion in terms of random collisions between a microscopic particle and much smaller, fast-moving molecules.

You will be able to

• Explain gas pressure in terms of particles colliding with the walls of the container.
• Calculate a new pressure or volume at constant temperature using p₁V₁ = p₂V₂.
• Explain why the pressure of a gas at constant volume rises when its temperature rises.

You will be able to

• Sketch and interpret a heating curve and a cooling curve, identifying melting, boiling and freezing.
• Explain why the temperature stays constant during a change of state.
• Calculate the energy for a change of state using E = mL and for a temperature change using E = mcΔT.

You will be able to

• Describe an experiment to determine the specific heat capacity of a solid or a liquid.
• Calculate the energy supplied using E = VIt and the specific heat capacity using c = E ÷ (mΔT).
• Explain why energy lost to the surroundings makes the measured specific heat capacity too large, and how insulation reduces it.

You will be able to

• Describe experiments that show metals are better thermal conductors than non-metals, and explain conduction by lattice vibrations and free electrons.
• Explain convection currents in liquids and gases in terms of changes in density.
• Describe how the colour and texture of a surface affect the emission and absorption of infrared radiation.