No, the diatomic neon molecule (Ne2) does not exist under normal conditions.
Why Ne2 Does Not Form
The non-existence of Ne2 can be fundamentally explained by molecular orbital (MO) theory, which describes how atomic orbitals combine to form molecular orbitals when atoms bond. Neon (Ne) is a noble gas, characterized by its full valence electron shell, which makes it very stable and unreactive as a single atom.
When two neon atoms theoretically attempt to form a diatomic molecule (Ne2), the molecular orbitals that would be formed are populated by electrons. According to molecular orbital theory, the number of electrons that would occupy bonding molecular orbitals is exactly equal to the number of electrons that would occupy antibonding molecular orbitals.
This balance leads to a crucial concept known as bond order.
Understanding Bond Order
Bond order is a measure of the number of chemical bonds between a pair of atoms. It is calculated as half the difference between the number of electrons in bonding molecular orbitals and the number of electrons in antibonding molecular orbitals.
| Concept | Description | Result for Ne2 |
|---|---|---|
| Bond Order | (Number of electrons in bonding orbitals - Number of electrons in antibonding orbitals) / 2 | 0 |
| Implication | A bond order of zero signifies that there is no net attractive force between the two atoms, meaning a stable chemical bond cannot form. | No stable molecule forms |
Therefore, because the Ne2 molecule would have a bond order of zero, there is no net stabilization from bond formation. The repulsive forces between the nuclei and the filled electron shells are not overcome by any attractive forces, preventing the formation of a stable diatomic Ne2 molecule. This is why neon primarily exists as individual atoms.
