When an atom emits gamma radiation, what change occurs in its atomic mass?

• A. There is no change in atomic mass.
• B. The atomic mass decreases by 1 unit.
• C. The atomic mass decreases by 4 units.
• D. The atomic mass increases by 1 unit.

Answer: (A)

Verified step by step guidance

1. Understand that gamma radiation is a form of electromagnetic radiation emitted from the nucleus of an atom during radioactive decay.
2. Recall that gamma emission involves the release of energy without the emission of particles such as protons or neutrons.
3. Recognize that because no particles are lost or gained, the number of protons and neutrons in the nucleus remains unchanged.
4. Conclude that since atomic mass depends on the total number of protons and neutrons, and these do not change during gamma emission, the atomic mass remains the same.
5. Therefore, when an atom emits gamma radiation, there is no change in its atomic mass.