What typically occurs when energy in an atom is released?

• A. An electron moves from a lower energy level to a higher energy level, absorbing a photon.
• B. The nucleus of the atom splits into two smaller nuclei.
• C. The atom gains mass and becomes an isotope.
• D. An electron moves from a higher energy level to a lower energy level, emitting a photon.

Answer: (D)

Verified step by step guidance

1. Understand that when energy is released by an atom, it involves changes in the energy levels of electrons within the atom.
2. Recall that electrons occupy specific energy levels or orbitals around the nucleus, and they can move between these levels by absorbing or emitting energy.
3. When an electron moves from a higher energy level to a lower energy level, the atom releases energy in the form of a photon (a particle of light). This is the process of emission.
4. Recognize that the energy of the emitted photon corresponds exactly to the difference in energy between the two energy levels involved in the transition.
5. Therefore, the typical event when energy is released by an atom is an electron transitioning from a higher to a lower energy level, emitting a photon.