The phenomenon of radioactivity is observed in heavy elements like uranium. A French scientist Henri Becquerel first observed the decay of radioactive elements. The half-life of a radioactive element is the time required for the element to decay to half of the original amount. For instance, half-life is the time period during which half of the atom of a radioactive element undergoes a nuclear process to be reduced into a lighter element.
Process of Radioactive Decay
The process of radioactive decay is spontaneous and irreversible. In a decay, one element is transformed into another element by changing the number of protons in the nucleus of the element. Remember, it's the number of protons that defines an element. The atoms that are involved in the process of radioactive decay are called isotopes. There are mainly three types of radiation―Alpha radiation, Beta radiation, and Gamma radiation.
The process of an alpha decay occurs when the nucleus of an element has too many protons. The decay occurs because of the excessive repulsion of the protons. Emitting a helium nucleus reduces the repulsion. Helium emission takes place when a non-zero probability of transmission takes place in the nucleus of an atom.
A beta radioactive decay occurs when the ratio of the neutron to proton is great. When this condition occurs, a radioactive element becomes unstable. In the process of beta decay, a neutron turns into a proton and an electron, and the electron is emitted.
In a gamma decay process, a high-energy particle of gamma is released. This process occurs when the highly charged nucleus moves from a higher state to lower state.