Question

Which one of the elements with the following outer orbital configurations may exhibit the largest number of oxidation states?

• A. $3d^3,4s^2$
• B. $3d^5,4s^1$
• C. $3d^5,4s^2$
• D. $3d^2,4s^2$

Answer 1

Answer: (C)

$3d^5,4s^2$

Answer 2

The sum of number of electrons (unpaired) in

d-orbitals and number of electrons in s-orbital gives

the number of oxidation states (os) exhibited by a

d-block element. Therefore,

(a) $3d^3,4S^2 \Rightarrow OS = 3+2=5$

(b) $3d^5,4S^1 \Rightarrow OS = 5+1=6$

(c) $3d^5,4S^2 \Rightarrow OS = 5+2=7$

(d) $3d^2,4S^2 \Rightarrow OS = 2+2=4$

Hence, element with $3d^5,4S^2$ configuration exhibits

largest number of oxidation states.