Question

Using Slater's rules, what is the effective nuclear charge experienced by a valence electron in the Na+ ion?

Select one: a. 1.00 b. 2.20 c. 3.05 d. 6.85

Answer 1

We have to calculate effective nuclear charge experienced by a valence electron in the Na⁺ ion.

Na⁺: (1s²)(2s²,2p⁶)(3s⁰)

The electrons in interest are the 2P electrons, so for shielding

1. electrons within same group shield 0.35, except the 1s which shield 0.30
2. electrons within the n-1 group shield 0.85
3. electrons within the n-2 or lower groups shield 1.00

With the above values,
S[2p] = 1.00(0) + 0.85(2) + 0.35(5) = 3.45

And we know

Zeff=Z−S

And here Z is 11

Therefore Zeff=11-3.45= 7.55