What Is Meant By Radioactive Disintegration

Radioactive disintegration is a process of nuclear disintegration of a radioisotope in its effort to achieve a stable nucleus. We know that in the naturally available radioactive elements there are only two kinds of particles which could be ejected from its atoms:

1. The alpha (a) particle, which is really the nucleus of a Helium atom (⁴He) and carries away 4 mass particle and 2 atomic particles.
   
   _ZX^A - ₂a⁴ = _Z-2X^A
   
   Here X represents chemical symbol, Z is atomic number and A is mass number.
   
   
2. The other particle which could be ejected is beta (b) particle, which is an electron. It does not however, comes from an orbit, but from a neutron, which under certain circumstances, dissociates into a proton and an electron. The electron is not tolerated in the nucleus and is ejected immediately, but an extra positive charge (neutron replaced by a proton) is left in the nucleus. The new atom now has the same mass but the atomic number one higher than the old or previously possessed by it.
   
   _ZX^A - _-1b⁰ = _Z+1X^A

Uranium, Thorium and Radium are the best known naturally occuring radioactive elements. In 1934 it was documented that it was possible to create isotopes and radioisotopes by bombarding the stable elements with high energy subatomic particles. Except Hydrogen and Helium more than two isotopes have been created from every element by artificial manipulations. There are 21 isotopes of Iodine ranging from ¹¹⁹I to ¹³⁹I and out of these 20 are radioactive isotopes or radioisotopes except ¹²⁷I.

The artificially created radioactive isotopes or radioisotopes have the same radiations as those of natural ones. Some of them also emit protons or beta⁺ (b⁺) particles.

_ZX^A - ₊₁b⁰ = _Z-1X^A

Radioactive disintegration of radioisotopes results in the emission of only one type of above mentioned particles and radiation like x-rays called gamma (g) rays. The atoms of any particular radioactive element are destined to emit the same kind of radiation till its total disintegration; there is no way to switch on to any other type of radiation.