Rhenium Valence Electrons
Why rhenium has 7
Rhenium has 75 electrons, arranged as 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 4f14 5d5 6s2. Counting the 6s electrons plus the 5d electrons gives 7, the usual textbook convention for transition metals. Some courses count only the electrons in the outermost shell, which gives 2 for rhenium; check which convention your class uses.
Rhenium is a transition metal in group 7. Counting its outer s electrons plus the d electrons beneath them gives 7, the same as the group number.
What that means for bonding
Transition metals can lose different numbers of these electrons, which is why rhenium shows several oxidation states (+1, +2, +3, +4, +5, +6, +7). When it forms a cation it loses the 6s electrons first.
Electrons per shell: 2, 8, 18, 32, 13, 2. See the rhenium electron configuration and orbital diagram or the full rhenium data sheet.
Same group, same count
Rhenium valence electrons FAQ
How many valence electrons does rhenium have?
Rhenium has 7 valence electrons. Its electron configuration is 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f¹⁴ 5d⁵ 6s²; the count is 2 outer s + 5 d electrons; 2 in the outermost shell. If your course counts only outermost-shell electrons, the answer is 2.
How do you find the valence electrons of rhenium?
Rhenium is a transition metal in group 7. Counting its outer s electrons plus the d electrons beneath them gives 7, the same as the group number.
How many bonds does rhenium form?
Transition metals can lose different numbers of these electrons, which is why rhenium shows several oxidation states (+1, +2, +3, +4, +5, +6, +7). When it forms a cation it loses the 6s electrons first.