Conduction: Transfer of energy Fromm vibrating particles to neighbouring ones

Convection: Energetic particles move away from the hotter to cooler regions

Cavity Wall insulation: Made up of inner and outer walls with a gap full of air in the middle to decrease conduction

Loft insulation: Reduce a convection current being formed in a loft

Double-Glazed Windows: Same as cavity wall have two sheets with air in the middle to reduce conduction

Drought Excluders: around doors and windows reduces convection

The sun, wind, water waves hydro-electricity, bio-fuel, tides, geothermal

Set up a basic circuit with a voltmeter and ammeter with a ruler and a piece of wire attached to the ruler.

• Test each time with crocodile clips at different points on the ruler and record the results each time
• Using potential difference and current calculate resistance and plot a graph of resistance against length of wire

Beta - This is when an electron is ejected from the nucleus and a neutron is turned into a proton. Beta is more damaging outside the body but less damaging in the body

Gamma - This is when an atom isn't changed in terms of subatomic particles but it just gives out electromagnetic energy. Gamma is the most damaging outside the body but the least damaging inside the body

Alpha - This is when a helium nuclei is ejected from the nucleus containing 2 neutrons and 2 protons. Alpha is the least dangerous outside the body but the most dangerous inside the body

Radiation is a completely random process. You can't predict which atom or when will decay next

Half Life is the time for half of the atoms i an isotope to decay. it can be used to find the rate at which isotopes decay. This is its activity.

Background radiation comes from many sources and is constantly there. However it is a very low level so poses no real risk to us.

Sources include;

• Unstable isotopes in food, the air, building materials and rocks in the ground
• Radiation from space, cosmic rays. This is usually from the sun but the atmosphere protects us from the majority of this.
• Radiation from human activity, nuclear fallout or nuclear waste. This however is a tiny proportion of the background radiation

Exposure to radiation is called irradiation. Irradiation does not make you radioactive
.
Contamination is when radioactive particles are on objects. This is more dangerous as it could lead to consumption of the radiation source.

Uses of radiation

• Gamma rays can be used as medical tracers to track movement around the body
• Treatment of cancer using radiotherapy
• Both the risks and benefits have to be weighed up before it can be put into practice

This splits large heavy unstable elements and the resulting energy is what is used in nuclear power stations. Spontaneous fission is extremely rare, a neutron has to be absorbed first.

The products of fission are two smaller lighter atoms and two or three neutrons which can collide with other atoms causing them to fission as well. This is called a chain reaction.

The energy from fission is used to heat water and the resulting steam turns a generator.

This is the joining of two light atoms into one heavier atom(usually deuterium and tritium into helium). The only natural occurrence of this is in stars. The resulting energy is much greater than that of fission but it is a lot more dangerous and difficult.

Due to the difficulty of fusion it isn't widely used in industry yet but it would be extremely useful in the future due to the cleanliness of the procedure