Answer:
Electrons move from higher energy level to lower energy level emitting light
Step-by-step explanation:
Neon is a noble gas and inert in nature which means that it doesn't form bonds with any other atom but if enough electric voltage is applied to it electrons from it will be excited and move to high energy states although momentarily. When these electrons come back to their original energy states they release the excess energy in form of photons which is seen by us as the light coming from the neon light sources.