Radioactivity/ Spontaneous Decay of Radionuclide

 

Radioactivity is the spontaneous emission of certain particle by an atom or nuclide of substances, it is it is a spontaneous process and does need change in temperature, pressure or density.  It involves the emission of either alpha, beta particles or gamma rays.  A radioisotope is any isotope of an atom that is radioactive; it can also be called radionuclide or radioactive atoms.

The emission of either alpha  particle or beta particle result in change in the nuclear structure of the  atom and therefore new atom is formed. The emission of an alpha particle by radionuclide will result in lost of four in the atomic mass and two in that atomic number of the atom involve, likewise the emission of beta particle will result to increase or decrease in atomic number but the atomic mass of the atom does not change. A change in the atomic number will create a new atom which is entirely different from the former radionuclide

 An emission of an alpha atom which is a helium nuclei will result in  an tom which is less in atomic mass by four by less in proton number by less two to the parent nuclei.  An alpha particle is a helium nuclei. An emission of a beta particle will result in an atom which has one proton less or greater than the parent nuclides, therefore beta decay can be either electron capture of beta emission,

What cause the spontaneous decay instability of the radionuclides, they are unstable due   their low binding energy. Therefore they emit radiation continuous and change from one nuclide to another until they attend a stable nuclei.

The radiation emit by this radioisotopes can be detected using several method base on the properties of the emitted radiations. Alpha particles are helium nuclei , they are positive charge   while beta particles are stream of moving electrons, therefore they are negatively charged and gay rays are electromagnetic radiations and therefore are electrically neutral, when this radiation are subjected to electromagnetic fields, they alpha particles will be deflected to the negative electric poles , the particle will be deflected to the positive electric poles while the gamma ray will remain undeflected.

The general properties of the radiations can be summarized as follows;

·         They are particles

·         They are helium nuclei he,

·         They are positively charged

·         They cause heavy ionizations

·         They fluorescence in zincsulphide

·         Penetrate several centimeters of air and hundredth millimeters of  solid materials

·         Deflected by both electrical and magnetic field

Properties of beta particles

·         They stream of electrons

·         They are negatively charged

·         They are either positron or negatron

·         Less ionistion than alpha particles

·         Deflected by both electrical and magnetic field

·         Much penetrating power than alpha

·         Velocity ranges from 0 to 0.995 of the speed of light

·         They also fluorescence

Properties of gamma rays

·         They are electromagnetic rays

·         Speed is same as speed of light about 3 x10⁸m/s

·         Low ionization

·         Most penetrating