Fine the magnetic moment of a divalent ion in aqueous solution if its atomic number is 25

Options

(a) 3.9 B.M.
(b) 4.49 B.M.
(c) 5.9 B.M.
(d) 6.9 B.M.

Correct Answer:

5.9 B.M.

Explanation:

Magnetic Moment (µ) = √n(n+2). Where n = number of unpaired electrons. Atomic Number 25 = 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁵ 4s². n = 5. Therefore it is divalent so 4s⁰ in M²⁺ and n = 5. Therefore µ = √5(5+2) = √5 *7 = √35. = 5.916 BM = 5.9 B.M.