When an atom absorbs energy, which of the following occurs?

• A. The atom loses a proton from its nucleus.
• B. The nucleus splits into two smaller nuclei.
• C. The atom becomes negatively charged by gaining an extra electron.
• D. An electron moves to a higher energy level.

Answer: (D)

Verified step by step guidance

1. Understand that when an atom absorbs energy, the energy affects the electrons rather than the nucleus or the overall charge of the atom.
2. Recall that protons are located in the nucleus and are not lost during typical energy absorption processes; losing a proton would change the element itself, which is not what happens here.
3. Recognize that the nucleus splitting into two smaller nuclei refers to nuclear fission, a process unrelated to simple energy absorption by an atom.
4. Know that gaining an extra electron would make the atom negatively charged (an ion), but absorbing energy alone does not cause the atom to gain or lose electrons.
5. Therefore, the correct process is that an electron absorbs the energy and moves from a lower energy level (ground state) to a higher energy level (excited state), which is a fundamental concept in atomic structure and spectroscopy.