Question

Chromium has the electronic configuration $4s^{1}3d^{5}$ rather than $4s^{2}3d^{4}$ because

• A. $4s$ and $3d$ have the same energy
• B. $4s$ has a higher energy than $3d$
• C. $4s^{1}$ is more stable than $4s^{2}$
• D. $4s^{1}3d^{5}$ half-filled is more stable than $4s^{2}3d^{4}$

Answer 1

Answer: (D)

$4s^{1}3d^{5}$ half-filled is more stable than $4s^{2}3d^{4}$

Answer 2

$Cr$ has $\lbrack Ar\rbrack 4s^{1}3d^{5}$ electronic configuration because half filled orbital are more stable than other orbitals.