Humber Admissions Practice Test

When an atom gains electrons, what kind of ion does it become?

1. Cation

2. Anion

3. Neutral atom

4. Radical

The correct answer is: Anion

When an atom gains electrons, it becomes negatively charged due to the increase in the number of negatively charged electrons compared to the positively charged protons in the nucleus. This results in the formation of an anion. Anions are a type of ion specifically formed when there is a surplus of electrons, which leads to an overall negative charge. In contrast, cations are formed when an atom loses electrons and thus has a higher number of protons than electrons, resulting in a positive charge. A neutral atom remains electrically balanced with equal numbers of protons and electrons, while a radical often involves an atom or molecule that has unpaired electrons and is generally more reactive. The focus here is on the process of gaining electrons, which directly correlates to the formation of an anion.