Ion charge for pdtwo elements in the second transition series ( y through cd ) have four unpaired electrons in their 3+ ions. what elements fit this description
Answer is: Technetium (chemical element with symbol Tc and atomic number 43) and rhodium (symbol Rh and atomic number 45).
1) Electron configuration of technetium: ₄₃Tc 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4p⁶4d⁵5s². In 3+ ion three valence electrons are removed: ₄₃Tc³⁺ 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4p⁶4d⁴, four unpaired electrons are in 4d orbital. 2) Electron configuration for rhodium: ₄₅Rh 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4p⁶4d⁸5s¹. In 3+ ion three valence electrons are removed: ₄₅Rh³⁺ 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4p⁶4d⁶, in 4d orbital four electrons are unpaired and two electrons are paired.
