Mass energy equivalence:-
The physical principle that a measured quantity of energy is equivalent to a measured quantity of mass. The equivalence is expressed by Einstein's equation E = mc 2 , where E represents energy, m the equivalent mass, and c the speed of light.
Give one example:-
For example, the collision of an electron and a proton annihilates the mass of both particles, but creates energy in the form of photons.
Mass defect:- We know that atomic nucleus consists of proton and neutron. It is found that measure mass of a nucleus is always less than. The sum of masses of the individual protons and neutrons which makes it up. This is known as mass defect.
OR
We know that an atom consists of protons, neutrons, and electrons; each one of which possesses a finite mass. However, the weight of an atom is always less than the sum of the weights of its protons, neutrons, and electrons. The difference is known as the mass defect.
Binding energy:- The energy required to split (to overcome) nucleus of an atom into its component parts. The components parts are protons and neutrons.
OR
Binding energy is defined as the amount of energy that must be supplied to a nucleus to completely separate its nuclear articles (nucleons)