PSI Barbering Practice Exam

What do you call an ion that has a negative charge?

1. Cation

2. Radical

3. Anion

4. Neutral ion

The correct answer is: Anion

An ion that has a negative charge is specifically referred to as an anion. This term comes from the Greek word "anion," which means "to go up." Anions are formed when an atom gains one or more electrons, resulting in a net negative charge. This gaining of electrons occurs because the number of negatively charged electrons now exceeds the number of positively charged protons in the nucleus of the atom. Understanding the nature of anions is important, especially in the context of chemical reactions and compounds, where they often play a crucial role in the formation of salts and other substances. For instance, in the common table salt, sodium chloride, the chloride ion (an anion) combines with a sodium ion (a cation) to create a neutral compound. The other terms, such as cation, radical, and neutral ion, refer to different classifications of chemical entities. Cations are positively charged ions formed by the loss of electrons, radicals are atoms or molecules that have unpaired electrons and thus are highly reactive, and neutral ions have an equal number of protons and electrons, leading to no overall charge. Understanding these differences can help clarify the behavior of ions in various chemical contexts.