The atomic number of elements A and B is 9 and 17 respectively. Why is element a better oxidant than B?

Explanation

The electronic configuration of A is `1s^2 2s^2 2p^5` and that of B is `1s^2 2s^2 2p^6 3s^2 3p^5`. The maximum Principal Quantum Number of A is 2 and that smaller than that of B. Hence the capacity of electron drag (electronegativity factor) is more for A, than that of B. Thus 'A' is a better oxidising agent than 'B'.