Quantum is a discrete and the smallest natural unit of energy and momentum. Planck makes the assumption that every energy transfer on a sub-atomic level consist of small units, called quanta. The view of electromagnetic energy as photons reflects this quantization.
E = h x v
E = energy
h = Planck quantum of action = 6.6261 x 10^-27 erg sec
v = frequency.

A gamma quantum is a distinct photon of electromagnetic radiation with the highest energy, shortest wavelength. The energy of a single photon is above 100 keV, the wavelength is below about 10 picometers. Gamma photons are generated by processes within the atomic nuclei.

See also Quantum.

Binding energy is equal to the amount of energy which is used to free electrons or disintegrate nuclides from their atomic bond.
The electron binding energy of a hydrogen atom is with 13.6 eV very low. The nuclear binding energy of an alpha-particle, energy equivalent of the sum of the individual masses of nuclides minus the mass of the whole nucleus, is 28.3 MeV.

See also Alpha Decay, Beta Decay and Gamma Quantum.