The difference between the sum of masses of all nucleons( M) mass of the nucleus( m) is called mass defect.
Mass Defect( Δm) = M – m = [ Zm p +( A – Z) m n – m n ]
Nuclear Binding Energy
The minimum energy required to separate the nucleons up to an infinite distance from the nucleus, is called nuclear binding energy.
Nuclear binding energy per nucleon = Nuclear binding energy / Total number of nucleons
Binding energy, E b = [ Zm p +( A – Z) m n – m N ] c 2
Packing Fraction( P)
p =( Exact nuclear mass) –( Mass number) / Mass number
= M – A / M
The larger the value of packing friction. greater is the stability of the nucleus.
[ The nuclei containing even number of protons and even number of neutrons are most stable.
The nuclei containing odd number of protons and odd number of neutrons are most instable.]
Radioactivity
The phenomena of disintegration of heavy elements into comparatively lighter elements by the emission of radiations is called radioactivity. This phenomena was