Question

The correct ground state electronic configuration of chromium atom is

• A. $\lbrack Ar\rbrack 3d^{5}4s^{1}$
• B. $\lbrack Ar\rbrack 3d^{4}4s^{2}$
• C. $\lbrack AR\rbrack 3d^{6}4s^{0}$
• D. $\lbrack Ar\rbrack 4d^{5}4s^{1}$

Answer 1

Answer: (A)

$\lbrack Ar\rbrack 3d^{5}4s^{1}$

Answer 2

3d subshell filled with 5 electrons (half-filled) is more stable than that filled with 4 electrons. $1,4s$ electrons jumps into $3d$ subshell for more sability.