Question

NeF2 and HeF2 don't exist.Why?​

Answer 1

Answer:

Even if Ne can expand its octet, Ne's valence electrons are close to the nucleus and thus experience strong electrostatic attraction. To unpair them and move it to a higher energy orbital will need high amount of energy which can not be compensated by the formation of the Ne-F bond. Hence NeF2 does not exist.