Question

Which of the following oxidation state is common for all lanthanoids?

• A. \(+2\)
• B. \(+3\)
• C. \(+4\)
• D. \(+5\)

Hint:

Most common oxidation state of lanthanoids: \[ +3 \] due to stable removal of: \[ 6s^2 \] and one additional electron.

Answer 1

The Correct Option is B

Step 1: Recall the common oxidation state of lanthanoids.
Lanthanoids generally lose: \[ 2\ \text{electrons from }6s \] and: \[ 1\ \text{electron from }5d\text{ or }4f \] Thus the most stable and common oxidation state is: \[ +3 \]

Step 2: Analyze other oxidation states.
Some lanthanoids may also show: \[ +2 \quad \text{or} \quad +4 \] but these are not common to all lanthanoids.

Step 3: Identify the correct option.
Therefore: \[ \boxed{ \mathrm{ (B)\ +3 } } \]