We have to explain how we can modify Slater’s rules to adjust for the difference in electronic penetration of the nucleus for the 2s and 2p orbitals.
Slater’s rules allow us to calculate the effective nuclear charge (Zeff) experienced by an electron.
Outer electrons experience less nuclear charge than the inner electrons because inner electrons screen (shield) the outer electrons from the nucleus.
The orbitals that belong to the same energy level (n) are called a group. For example, 3s, 3p and 3d all belong the the n=3 energy level therefore, they belong within the same group.
Slater’s rules for electrons in s and p orbitals are:
- Electrons in the same group shield 0.35, except 1s orbital which shields 0.30.
- Electrons in the n-1 group shield 0.85.
- Electrons in the n-2 or lower groups shield 1.00.