Bond order: 1.
How many chemical bonds in a H₂ molecule?
There is one valence electron in each neutral H atom. Refer to a periodic table. H is one electron away from the closest noble gas: He. The H atoms need to achieve the noble gas configuration of He to be stable. For that, each H atom needs one more electron. There are two H atoms in an H₂ molecule. It will take 2 × 1 = 2 more electrons for both H atoms in each H₂ molecule to become stable.
Unlike ions, the H₂ molecule is neutral. There's no no extra electron for the H atoms. The two atoms need to share electrons with each other by forming chemical bonds. One chemical bond adds one electron to both bonding atoms. As a result, each bond will add two electrons to the molecule.
The H₂ molecule needs 2 extra electrons, which corresponds to 2 / 1 = 1 chemical bond.
What's the bond order?
[tex]\displaystyle\text{Bond Order} = \frac{\text{Number of Bonds}}{\text{Number of Bonding Sites}}[/tex].
The two H atoms in an H₂ molecule forms
As a result,
[tex]\displaystyle\text{Bond Order} = \frac{\text{Number of Bonds}}{\text{Number of Bonding Sites}} = \frac{1}{1} = 1[/tex].
