2 ways to find bond order of He₂

   how to determine bond order of He₂

1. Draw the molecular orbital diagram for He₂ (helium molecule)
   total number of electrons in He₂ is 4
   because atomic number of helium is 2
   two helium atoms in He₂
   2x number of atom =0
   2 × 2 = 4
   electronic configuration of He₂  is σ1s², σ*1s²
2. The number of bonding molecular orbital electrons (2) and the number of anti-bonding molecular orbital electrons (2).
3. Subtract the number of anti-bonding electrons from the number of bonding electrons: 2 – 2 = 0
4. Divide the result by 2:     0/ 2 = 0

         So, the bond order of He₂ is 0
         hence it is proved
        The bond order of He₂ is 0 because so He₂ do not exist in nature

Note: if you want  bond order of O₂ click here

if you want to see more information about bond order, click here