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

• A. The electron moves to a higher energy level (excited state).
• B. The electron is ejected from the atom and becomes a free electron.
• C. The electron's mass increases.
• D. The electron moves to a lower energy level (ground state).

Answer: (A)

Verified step by step guidance

1. Understand that electrons in an atom occupy specific energy levels or orbitals, with the lowest energy level called the ground state.
2. When an electron absorbs energy, it gains enough energy to move from its current energy level to a higher one; this is called an excited state.
3. Recognize that the electron does not increase in mass when it absorbs energy; its mass remains constant.
4. Note that the electron is not ejected from the atom unless it absorbs enough energy to overcome the ionization energy, which is not stated here.
5. Therefore, the correct interpretation is that the electron moves to a higher energy level (excited state) upon absorbing energy.