State one detector of gamma radiation
- Photographic film
- GM Tube
- Bubble chamber
State one source of gamma radiation
- Stars
- Some radioactive substances (e.g. Cobalt 60)
State one use for gamma radiation.
- Used as a tracer in medicine
- Used to treat cancer
- Sterilisation of operating instruments
- In industry, radioactive “tracer” substances can be put into pipes and machinery, then we can detect where the substances go.
- Gamma rays kill microbes, and are used to so that it will keep fresh for longer. This is known as “irradiated” food.
- Checking for cracks in aeroplane wings and joints
What are the three types of radiation?
- alpha
- beta
- gamma
What is meant by ionisation?
It is when an atom gains or loses an electron to become charged.
Which is the most ionising radiation?
alpha
Which is the least ionising radiation?
Gamma
What is meant by shielding?
Shielding means having something that will absorb radiation between you and the source of the radiation.
How can you reduce your exposure to radiation when you are working with it?
- Limit the time you have the source out (only get it when you need it)
- Handle only using tongs
- Keep the source at arm’s length
- Wash hands before and after use
- Do not eat while handling it
- Wear lead lined gloves/apron and safety goggles
What is meant by background radiation?
It is the radiation that is all around us.
State a source of man-made background radiation.
1) Weapons testing
2) Waste from the Nuclear industry
3) Medical uses: Having an X-ray, CT scan, barium meal etc.
State a source of natural background radiation.
1) Rocks: Some rocks such as granite or pitchblende are high in radioactivity
2) Food: Food can be slightly radioactive because of the soil it has been grown in.
3) Body: Contains Potassium 40 which is radioactive.
4) Cosmic Rays: Radiation from the Sun and outer space. The atmosphere will absorb most of this.
5) Radioactive gases: Radon and Thoron gases make up most of the dosage you will receive from background radiation. The gases come from rocks underground and the amount you are exposed to depends on the geology of where you live.
Give at least 2 uses for gamma radiation.
- Gamma rays are used for radiotherapy which is a cancer treatment
- Thickness control of paper or metal sheet for example.
- Gamma radiation can be used to sterilise medical instruments
- Radio-carbon dating
- Tracers - can be used in industry in pipes to look for cracks or in the human body to check for blockages
What is the fuel in a nuclear reactor?
Uranium
How does a nuclear power station produce electrical energy?
- The nuclear reactor uses fission of Uranium to produce large amounts of heat energy.
- The heat energy is used to heat a coolant which carries the heat to a heat exchanger where the heat from the coolant is used to heat water.
- The water which is heated, turns into steam, is piped to a turbine.
- The steam makes the turbine turn. (Heat energy to Kinetic Energy)
- The turbine turns the generator to create electrical energy. (Kinetic to Electrical energy)
Give an advantage of producing electricity using a nuclear reactor.
- Do not produce greenhouse gases – Carbon dioxide, methane, nitrous oxide
- Do not rely on fossil fuels which are in short supply
- Huge amount of energy from a small amount of fuel
- Small amount of waste produced
- Reliable source of energy (Unlike solar or wind)
Give a disadvantage of producing electricity using a nuclear reactor.
- The waste produced is radioactive. It has to be stored safely for a long time.
- Uranium is a non-renewable fuel.
- Risk of radioactive materials being released into the environment if there is an accident.
- Expensive to decommission nuclear power stations at the end of their useful life.
What are the particles in the nucleus called?
Protons and neutrons
What is the charge on a proton?
Positive
What is the charge on a neutron?
No charge
What is the charge on an electron?
Negative
In an atom which particle orbits the nucleus?
Electron
What are the main parts of an atom?
See diagram
What is the charge on a beta particle?
Negative
