Question

What is bond order of He2
Why It doesn't exists?​

Answer 1

Explanation:

He2 = 4 electron

sigma 1s2, sigma star 1s2, sigma 2s2 ,

sigma 1s2, sigma star 1s2, sigma 2s2 ,sigma star 2s2

So, bond order = 2-2/2 = 0/2 = 0

If bond order becomes zero it does not exists!

Hope it helps uh!

Answer 2

And total number of electrons available are 4. It means 2 electrons are in bonding molecular orbitals and 2 are in antibonding molecular orbitals . Since the bond order is zero so that He2 molecule does not exist...

Based on molecular orbital theory, He2 should not exist, and a chemical bond cannot form between the atoms. However, the van der Waals force exists between helium atoms as shown by the existence of liquid helium, and at a certain range of distances between atoms the attraction exceeds the repulsion....

Hope it helps...