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In which pair are BOTH species not expected to exist?
- H2+, He2-
- H2-, He2-
- H2(2+), He2
- H2-, He2+
Correct answer: H2(2+), He2
Solution
H2(2+) has no electrons (bond order 0) and He2 has equal bonding and antibonding electrons (bond order 0), so neither exists; the other listed ions have nonzero bond order.
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