Answer:
See explanation
Explanation:
Using Slater's rule;
the shielding experienced by an electron in an s- or p- orbital such as in Boron or oxygen is calculated based on the the fact that; electrons within same group shield 0.35, except the 1s which shield 0.30
Hence, for oxygen;
1s2 2s2 2p4
Zeff = (2× 0.3) + (5 × 0.35) = 2.35
For Boron
1s2 2s2 2p1
Zeff= (2 ×0.3) + {2 × 0.35) = 1.3
Hence the effective nuclear charge on a valence electron in boron is less than the effective nuclear charge on a valence electron in oxygen. Hence boron is larger than oxygen.