Radiation Revision Notes

Nuclear Fusion

Nuclear Fusion involves two small atomic nuclei joining to make a large nucleus. Energy is released when this happens. An example of this is: Hydrogen-1 nuclei fuse with Hydrogen-2 to make Helium-3 nuclei.

Nuclear Fission

Nuclear power reactors use a reaction called nuclear fission. Two isotopes in common use as nuclear fuels are uranium-235 and plutonium-239.

Splitting atoms: Fission is another word for splitting. The process of splitting a nucleus is called nuclear fission. Uranium or plutonium isotopes are normally used as the fuel in nuclear reactors, because their stoms have relatively large nuclei that are easy to split, especially when hit by neutrons. When either of these are hit by a neutron, the following happens:

1. The nucleus splits into two smaller nuclei, which are radioactive.

2. Two or three more neutrons are released.

3. Some energy is released.

Half-life

The half-life of a radioactive isotope is the time taken for the mass of the isotope to decrease to half its initial mass.

Activity

The activity of a radioactive isotope is the number of nuclei of the isotope to…