The correct option is A Assertion is true and reason is incorrect explanation for assertion
H+2=σ1s1
Bond order=Bonding electrons - Antibonding electrons2=1−02=0.5
Hydrogen molecule cation H+2: This molecule ion has only one electron. This electron is present in lowermost molecular orbital i.e, σ1s. So electronic configuration of H+2 is :(σ1s)1 and
H2:(σ1s)2
So, an electron is removed from the bonding orbital of H2 to form H+2 ion.