Question

Which of the following elements shows maximum number of different oxidation states in its compounds ?

• A. Eu
• B. La
• C. Gd
• D. Am

Answer 1

Answer: (D)

Oxidation states shown by elements are as follows:
$La=+3$
Eu and $Gd=+2$ and $+3$
$Am=+2+3+4+5$ and $+6$
Am shows maximum number of different oxidation state due to its larger size and low ionisation energy.