Work and Energy

Temperature

A measure of the average kinetic energy of particles in a substance.

Thermal Energy

Total energy of all the particles in a substance

Kinetic molecular theory

1. All matter is made of particles

2. Particles are in constant motion

3. Adding heat increases particle motion and thermal energy

Heat

Transfer of thermal energy

Conduction

Heat transfer through direct contact

Convection

Heat transfer where cooler denser fluid falls and pushes up warmer, less dense fluid

Radiation

Heat transfer through electromagnetic waves (e.g. sunlight)

Specific heat capacity

Amount of heat needed to raise the temperature of 1kg of a substance by 1 degree celsius.

Latent heat

Energy used to change state without a change in temperature

Radioactivity

Spontaneous emission of radiation

Radioactive decay

When the nucleus of an atom quickly changes, accompanied by the emission of particles or electromagnetic radation

Half-life

The average time it’ll take a radioactive material to decay to half it’s original mass

• Can be modelled mathematically

• Can be used to date fossils

Nuclear fission

• Reaction where big nucleus is split into smaller pieces

• Few emissions but many potential problems (waste heat, safety, economics)

Nuclear fusion

• Reaction when two small nuclei fuse together to form a larger nucleus

• More energy and less waste than fission

• Problem: How are we going to contain the plasma?

When there is an increase in heat, the liquid inside the bulb expands, pushing up into the tube. A decrease in heat lets the liquid contract, moving down the tube.

How does a thermometer work?

Same temperature

Relationship between freezing and melting point of most substances