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Q.
In which $5f$ subshell is half-filled?
The d-and f-Block Elements
Solution:
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