Correct Answer: B
Explanation:
The correct answer is b. The bond order can be calculated as the number of bonding electrons minus the number of anti-bonding electrons divided by two. In the case of H2, you have two electrons located in the sigma bonding orbital, then the bond order is 1. In H2+, you have only one electron located in a bonding orbital and anti –bonding orbital is empty, so it's 1/2.