Question

An element 'X' belongs to fourth period and fifteenth group of the Periodic Table. Which one of the following is true ?

• A. Partially filled 'd' orbitals and completely filled 's' orbitals.
• B. Completely filled 's' orbitals and completely filled 'p' orbitals
• C. Completely filled 's' orbitals and half-filled 'p' orbitals
• D. Half-filled 'd' orbitals and dompletely filled 's' orbitals
• E. Completely filled 'd', 's' and 'p' orbitals

Answer 1

Answer: (C)

Since the element 'X' belongs to fourth period and fifteenth group of Periodic Table, its outer electronic configuration is $4s^{2}4p^3$
Its complete electronic configuration is $1s^2,2s^2,2p^6,3s^{2}3p^6,4s^2,2d^{10},4p^3$Hence, its s. orbital is completely filled while p-orbital is half-filled.