National League for Nursing (NLN) Science Practice Exam

What is the term for a negatively charged ion?

1. Cation.

2. Anion.

3. Radical.

4. Isotope.

The correct answer is: Anion.

The term for a negatively charged ion is an anion. Anions are formed when an atom or molecule gains one or more electrons, resulting in a net negative charge due to the excess of negatively charged electrons compared to positively charged protons. This is fundamentally important in chemistry, as anions play a significant role in chemical reactions and bonding, especially in ionic compounds where they typically pair with positively charged ions known as cations. In contrast, cations, which are not the correct answer, refer to positively charged ions formed when an atom or molecule loses one or more electrons. The terms radical and isotope pertain to very different concepts; radicals are species that contain unpaired electrons, which can make them highly reactive, while isotopes refer to variants of elements that have the same number of protons but different numbers of neutrons, affecting their atomic mass but not their overall charge. Understanding these distinctions reinforces why the term anion correctly describes a negatively charged ion.