Question

Which of the following d-block element has half-filled penultimate as well as valence subshell?

• A. $Cu$
• B. $Au$
• C. $Ag$
• D. $Cr$

Answer 1

Answer: (D)

$Cr$

Electron configuration$-1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{1}3d^5$

Valance shell$-4s^1$(half filled)

Penultimate shell$-3d^5$

Chromium has half filled penultimate as well as valance subshell.