An orbital is identified by 3 quantum numbers, i.e. Principal quantum number, azimuthal quantum number and magnetic quantum number.
The set of numbers used to describe the electron’s position and energy in an atom are called quantum numbers.
- The three quantum numbers (n, l, and m) that describe an orbital are integers: 0, 1, 2, 3, and so on.
- The principal quantum number (n) cannot be zero. The allowed values of n are therefore 1, 2, 3, 4, and so on.
- The angular quantum number (l) can be any integer between 0 and n – 1. If n = 3, for example, l can be either 0, 1, or 2.
- The magnetic quantum number (m) can be any integer between –l and +l. If l = 2, m can be either -2, -1, 0, +1, or +2.