When an atom loses a neutron, which of the following best describes the result?

• A. The atom gains a positive charge and becomes a cation.
• B. The atom becomes unstable and immediately decays into protons.
• C. The atom changes into a different element.
• D. The atom becomes a different isotope of the same element.

Answer: (D)

Verified step by step guidance

1. Understand the structure of an atom: it consists of protons, neutrons, and electrons. Protons determine the element's identity (atomic number), neutrons contribute to the atomic mass but do not affect the element's identity, and electrons determine the charge.
2. Recognize that losing a neutron changes the number of neutrons in the nucleus but does not change the number of protons. Since the number of protons remains the same, the element itself does not change.
3. Recall that isotopes are atoms of the same element that have the same number of protons but different numbers of neutrons. Therefore, losing a neutron results in a different isotope of the same element.
4. Note that losing a neutron does not affect the electrical charge directly, so the atom does not become a cation (which requires loss or gain of electrons).
5. Conclude that the correct description is that the atom becomes a different isotope of the same element because only the neutron count changes, not the proton count or charge.