Which of the following statements correctly describes how energy is absorbed by an atom?

• A. An atom absorbs energy only when it loses a proton.
• B. An atom absorbs energy when its nucleus splits into two smaller nuclei.
• C. An atom absorbs energy when an electron transitions from a higher energy level to a lower energy level.
• D. An atom absorbs energy when an electron transitions from a lower energy level to a higher energy level.

Answer: (D)

Verified step by step guidance

1. Understand that atoms absorb energy when electrons move from a lower energy level to a higher energy level, which means the electron gains energy to jump to an excited state.
2. Recall that when an electron transitions from a higher energy level to a lower energy level, it releases energy, often in the form of light (emission), not absorption.
3. Recognize that losing a proton changes the identity of the atom (changing the element), which is not related to energy absorption in typical atomic transitions.
4. Note that splitting the nucleus (nuclear fission) involves nuclear energy, which is a different process from electronic energy absorption in atoms.
5. Conclude that the correct description of energy absorption by an atom involves electrons moving from lower to higher energy levels, absorbing discrete amounts of energy (quanta).