Ncert Exercises & Solutions

The actinoid that can show oxidation states up to +7 is:

1. Am

2. Th

3. U

4. Np

HINT: Only two elements show +7 oxidation state in actinoids i.e Pu and Np

Explanation :

Step 1:

The oxidation states of the following actinoids are as follows:

(1) Americium (Z = 95); Electronic configuration = $[Rn] 5 f^{7} 6 d^{0} 7 s^{2}$

Oxidation states shown by Am = +3, +4, +5, +6

(2) Thorium (Z = 90); Electronic configuration = $[Rn] 6 d^{2} 7 s^{2}$

Oxidation states shown by Th = +4

(3) Uranium (Z= 92); Electronic configuration = $[Rn] 5 f^{3} 6 d^{1} 7 s^{2}$

Oxidation states shown by U = +3,+4,+5,+6

(4) Neptunium (Z=98); Electronic configuration = [Rn]5f⁴6d¹7s²

Step 2:

Oxidation states shown by Np = +3,+4,+5,+6,+7