Question

What is the number of unpaired electrons in Lutetium (Lu) in the +3 oxidation state?

• A. 2
• B. 1
• C. 0
• D. 3

Hint:

The number of unpaired electrons can be determined by examining the electron configuration in the oxidation state of the element. If all electrons are paired, the element has no unpaired electrons.

Answer 1

The Correct Option is C

The number of unpaired electrons in Lutetium (Lu) at the +3 oxidation state is determined by its electronic configuration. Lutetium, with atomic number 71, has the ground state electron configuration: [Xe] 4f¹⁴ 5d¹ 6s²

In the +3 oxidation state, Lutetium loses three electrons. These are removed from the outermost shells, prioritizing 6s then 5d: 

• Two electrons are removed from 6s.
• One electron is removed from 5d.

Consequently, the electron configuration of Lu³⁺ is: [Xe] 4f¹⁴

The 4f sublevel contains 14 electrons, which fully occupies it. A completely filled sublevel lacks unpaired electrons.

Therefore, Lutetium in the +3 oxidation state has 0 unpaired electrons.