The increasing order of the first ionization enthalpy of the elements B, P, S and F (lowest first) is

Options

A. `B lt P lt S lt F`
B. `b lt S lt P lt F`
C. `F lt S lt P lt B`
D. `P lt S lt Blt F`

Answer

B

Explanation

B and F lie in the 2nd period while P and S lie in charge `Delta_(i) H_(1) `of P and S are higher than that of B but lower than that of F. Among P and S, P has higher `Delta_(i) H_(1) ` due to exactly half- filled configuration .Thus the overall increasing order of `Delta_(i) H_(i)` is : `B lt S lt P lt F` , i.e., option ( b) is correct.