Algonquin College Health Program Assessment (AC-HPAT) Practice Exam

What typically happens to an atom when it gains an electron?

1. It becomes a cation

2. It becomes an anion

3. It loses its neutrality

4. It forms a covalent bond

The correct answer is: It becomes an anion

When an atom gains an electron, it results in the atom having more electrons than protons, which causes it to carry a negative charge. This transformation defines the atom as an anion. Anions are negatively charged ions that are formed when atoms do not have an equal number of protons (which carry a positive charge) and electrons (which carry a negative charge). In contrast, a cation is produced when an atom loses electrons, leading to a positive charge. While gaining an electron does lead to a loss of electrical neutrality (which is mentioned in another choice), it specifically creates a negatively charged species, hence the classification as an anion is more precise. Forming a covalent bond refers to the sharing of electrons between atoms, which does not directly relate to the single action of gaining an electron. Therefore, the most accurate characterization of the process when an atom gains an electron is that it becomes an anion.