What is meant by the phrase, “the energy of an electron in a given orbital is quantized”?

Question

Need help explaining this, as I'm not confident with the definition of quantized energy.

Answer 1

This means it has a very specific amount of energy. The energy differs in each level (n) within the atom. Electrons in the atom exist in specific every levels and don't exist in between these levels, so they have specific energies and don't have energies in between these specific values. Quantized simply means "specific amounts or specific quantities". Quanta are "packets of energy". When an electron falls from one level to a lower one, it release energy in quanta or in specific amounts. If the electron goes from a lower to a higher level, it absorbs a certain quanta of energy.