Uses of radiation in radioactive dating back dating tools
If nuclei come close enough together, they can interact with one another through the strong nuclear force, and reactions between the nuclei can occur. Two major classes of nuclear reactions are of importance: fusion and fission.
As in chemical reactions, nuclear reactions can either be exothermic (i.e. Fusion is a nuclear process in which two light nuclei combine to form a single heavier nucleus.
An example of a fusion reaction important in thermonuclear weapons and in future nuclear reactors is the reaction between two different hydrogen isotopes to form an isotope of helium: This reaction liberates an amount of energy more than a million times greater than one gets from a typical chemical reaction.
Such a large amount of energy is released in fusion reactions because when two light nuclei fuse, the sum of the masses of the product nuclei is less than the sum of the masses of the initial fusing nuclei.
Nuclear half-lives range from tiny fractions of a second to many, many times the age of the universe.
Gamma rays can be emitted when a nucleus undergoes a transition from one such configuration to another.This can be written as an equation analogous to a chemical reaction.For example, for the decay of an isotope of the element seaborgium, ray's wavelength is much shorter.Because the reacting nuclei are both positively charged, there is a large electrostatic repulsion between them as they come together.Only when they are squeezed very close to one another do they feel the strong nuclear force, which can overcome the electrostatic repulsion and cause them to fuse.