CH1012
                                         L1 /   
‹#›
                                         L1 /   
10
THE He2 MOLECULE
Bond order = 1/2 [no of e- in bonding MOs -
                         no of e- in antibonding MOs]
Bond order > 0 means a stable molecule.
Bond order = 0 means it doesn’t exist.
C10F27 C10F27
He2+
He2
doesn’t exist                                      exists