Question

1. when an electron moves from a higher energy level to a lower one, what happens?

energy is absorbed by the atom.
the atom is excited to a higher energy state.
the atomic number of the atom decreases.
a photon of light is emitted by the atom.
clear all

Explanation:

To solve this, we analyze each option:

• "Energy is absorbed by the atom": When an electron moves to a lower energy level, energy is released, not absorbed. So this is incorrect.
• "The atom is excited to a higher energy state": Moving to a lower energy level is the opposite of excitation (which involves moving to a higher level). Incorrect.
• "The atomic number of the atom decreases": Atomic number depends on protons, not electron energy level changes. Incorrect.
• "A photon of light is emitted by the atom": When an electron transitions from a higher to lower energy level, the excess energy is released as a photon (light). This is correct.

Answer:

D. A photon of light is emitted by the atom.