Question:
Which is the last element in the series of the actinoids? Write the electronic configuration of this element. Comment on the possible oxidation state of this element.
Solution:
The last element in the actinoid series is lawrencium, $\mathrm{Lr}$. Its atomic number is 103 and its electronic configuration is $[\mathrm{Rn}] 5 f^{14} 6 d^{1} 7 s^{2}$. The most common oxidation state displayed by it is $+3$; because after losing 3 electrons it attains stable $f^{14}$ configuration.