The atoms and electrons in a table..............do not stay in one place........they move around..................4th d could also be movement.......................

When properly stimulated, electrons in these materials move from a lower level of energy up to a higher level of energy and occupy a different orbital. ... This is because of the quantum nature of the atoms being used in the LED and the quantum energies of the electrons within them.

Electrons and Energy - BIOdotEDU

www.brooklyn.cuny.edu/bc/ahp/LAD/C3/C3_elecEnergy.html