1What makes up an atom?
Proton, neutron, electron, shells
2What are isotopes?
atoms of an element that have the same number of protons but different numbers of neutrons
3What happens when too many neutrons are removed from the nucleus?
The nucleus becomes unstable and begins to seperate
4What are alpha particles made of?
2 protons and 2 neutrons; they have a positive charge and a mass of 4
5What are beta particles made of?
They start off as a neutron, which becomes a proton before becoming an electron; this gives it a negative charge
6What is gamma radiation made of?
They’re made of waves that have no charge or mass
7What is ionisation?
when an atom loses an electron
8Why is ionisation dangerous?
it can damage the DNA in our cells and can cause canerous mutuations
9What is the range and penetration limit of alpha, beta and gamma?
Alpha- can only travel a few centimetres in the air & is blocked by skin or paper
Beta- can travel a few metres in air & can be blocked by wood or thin aluminium
Gamma- can travel for very long distances & can be blocked by lead
10In a magnetic field, where would each form of radiation deflect to?
Alpha: deflects to the negative side of a magnetic field
Beta: deflects to the positive side of a magnetic field
Gamma: doesn’t deflect at all; passes straight through
11What is background radiation?
radiation that’s found in the environment at a safe level; usually comes from naturally occuring sources like radon gas, cosmic rays and humans. Measured with a Geiger-Muller tube and measured in Becquerel’s
12What are radiation doses measured in?
Sieverts or millisieverts ( SV or mSV)
13What is half-life?
the time taken for half of all the nuclei in a radioactive element to decay
14What is contamination?
the unwanted presence of of radioactive materials on the body
15What is irradiation?
when radioactive sources are exposed to a person: DOESN’T INHERENTLY MEAN YOU’RE CONTAMINATED
16What are alpha particles used for?
used in smoke detectors: the particles ionise the air to create a current that’s interrupted by smoke, which triggers the alarm
17What are beta particles used for?
used for thickness control in paper production and carbon dating of remains and fossils
18What are gamma rays used for?
radiotherapy and sterilisation of medical equipment and food
19What is nuclear fission?
where the nucleus of an atom splits to form the nuclei of other atoms
20What form of uranium is used in power plants?
Uranium-235
21What happens in nuclear reactors?
1. Uranium control rods are in a reactor vessel
2. Neutrons are fired at the rods and causes a chain reaction, which releases energy as heat- this heat warms up water and produces steam
3. A turbine is linked to the generator and the national grid; the steam turns the turbine
4. The steam condenses into water and is reused
22What do different components of the reactor do?
Moderator: slows down the neutrons
Fuel rods made from uranium-235: undergoes fission and releases energy and neutrons
Control rods: absorbs excess neutrons; made from boron