parity selection rule sentence in Hindi

Examples

1. This transition is strictly forbidden by spin, symmetry, and parity selection rules; hence, direct excitation of ground state oxygen by light to form singlet oxygen is very improbable.
2. They are not observed due to strong but not absolute suppression, by spin-parity selection rules ( for beta decays and isomeric transitions ) or by the thickness of the potential barrier ( for alpha and cluster decays and spontaneous fission ) .-- ->