The period number in the long form of the periodic table is equal to :
| 1. | Magnetic quantum number of any element of the period. |
| 2. | Atomic number of any element of the period. |
| 3. | Maximum principal quantum number of any element of the period. |
| 4. | Maximum azimuthal quantum number of any element of the period. |
HINT: Period represent the shell number .
Explanation:
