Question

The halogen having five vacant orbitals in the outermost shell belongs to

• A. 3rd period
• B. 4th period
• C. 2nd period
• D. 5th period

Answer 1

Answer: (A)

Five vacant orbitals (3-$d$ level) are present in $C{l}_2$.
$(1s^{2}2s^{2}2p^{6}3s^{2}3p^5)$ which belongs to 3rd period