Question

$Gd(64)$ gives an oxidation state of only $+3$ because:

• A. It contains 3 unpaired electrons
• B. In +3 oxidation state it has unstable configuration
• C. In +3 oxidation state it has stable configuration
• D. There are 3 electrons present in 4 f in +3 oxidation state

Answer 1

Answer: (C)

In $+3$ oxidation state its configuration is $4f^7,5d^0,6s^0$ which is stable as per the rule of extra stability.