Question

How many outer-shell d electrons are there in each of the following transition-metal ions?

Re(III) =
Sc(III) =
Ru(IV) =
Hg(II) =

Answer 1

The answer to your question is:

Re (III) has 5 electrons

Sc(III) = has 1 electron

Ru(IV) = has 6 electrons

Hg(II) = has 10 electrons

Step-by-step explanation:

75 Re(III) = 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d⁵

21 Sc(III) = 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹

44 Ru(IV) = 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d⁶

80 Hg(II) = 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰