Question

In which $5f$ subshell is half-filled?

• A. $Am$ and $Cm$
• B. $Cm$ and $Bk$
• C. $Cm$ and $No$
• D. $No$ and $Am$

Answer 1

Answer: (A)

Americium $\left(Z=90\right)$ and curium $\left(Cm,Z=90\right)$ have $\left[Rn\right]5f^{7}6d^{0}7s^2$ and $\left[Rn\right]5f^{7}6d^{1}7s^2$configuration, respectively