General configuration of outermost and penultimate shell is `(n - 1) s^(2) (n - 1) p^(6) (n - 1)d^(x) ns^(2)`. If `n = 4` and `x = 5` then no. of protons in the nucleus will be

Options

A. `lt 24`
B. 25
C. 24
D. `gt 25`

Explanation

The element having outer electronic configuration `3s^(2)sp^(6), sd^(5)4s^(2)` has atomic number 25. Therefore, the number of protons is 25.