Question

In ground state of chromium atom $(Z=24)$ the total number of orbitals populated by one or more electrons is?

• A. $15$
• B. $16$
• C. $20$
• D. $14$

Answer 1

Answer: (A)

$15$

The configuration of ${}_{24}Cr$ is $1s^2,2s^2,2p^6,3s^2,3p^6,3d^5,4s^1$
$\therefore$ total s-orbitals$=4$
total p-orbitals$=6$
total d-orbitals$=5$ and thus
Thus, total orbitals $=4+6+5=15$.