The free gaseous `Cr` atom has six unpaired electrons.
Half-filled s-orbital has greater stability.

Options

A. If both assetion and reason are true and the reason is the correct explanation of the assertion.
B. If both assertion and reason are ture but reason is not the correct explanation of the assertion.
C. If assertion is true but reason is false.
D. If assertion is false but reason is true.

Answer

C

Explanation

Assertion : Electron configuration of `Cr (g)` is `[Ar] 1^(8) 3 d^(5) 4 s^(1)` and, therefore, it has six uparied electrons.
Reason : Fully filled orbital is more stable than half filled orbital on account of more number of exchange of electrons resulting into the greater release of exchange energy.