Radioactive Decay

Each element has one or more isotopes unstable nucleus will experience radioactive decay, causing the release core particles or electromagnetic radiation. Radioactivity can occur when the core radius is very large compared to the radius of the strong force (only works at a distance of about 1 fm). [66]

Forms of radioactive decay of the most common are: [67] [68]

     * Alpha decay, occurs when a nucleus emits an alpha particle (helium nucleus consisting of two protons and two neutrons). The results of this decay is a new element with atomic number smaller.
     * Beta decay, governed by the weak force, and generated by the transformation of neutrons into protons, or protons into neutrons. Transformation of neutrons into protons will be followed by emission of an electron and an antineutrino, when transforming a proton into a neutron followed by emission of a positron and a neutrino. Emission electron or positron emission referred to as beta particles. Beta decay can increase or decrease the size of a nucleus atomic number.
     * Decay gamma, produced by changes in the core energy level to a lower state, causing the emission of electromagnetic radiation. This can occur after the emission of alpha or beta particles from radioactive decay.

The types of radioactive decay of other less frequently include the release of neutrons and protons from the nucleus, emission is more than a beta particle, or decay resulting in the production of high-speed electron beam that is not beta, and production of high-energy photons of gamma rays that are not

Each radioactive isotope has a characteristic decay time period (half-life) which is the length of time required by half the amount of sample to decay out. The process of decay is exponential, so that after two half-lives, only 25% of the isotope will remain. [66]

Reverence : Wilkipedia