J is defined through J → = L → + S → {\displaystyle {\vec {J}}={\vec {L}}+{\vec {S}}} L being the orbital angular momentum and S the spin.
J didefinisikan melalui J → = L → + S → {\displaystyle {\vec {J}}={\vec {L}}+{\vec {S}}} L menjadi momentum sudut orbital dan S adalah spin.