Which term refers to an atom that gains electrons and carries a negative charge?

An anion is defined as an atom that has gained one or more electrons, resulting in a net negative charge. When an atom acquires additional electrons, it increases the number of negatively charged particles compared to positively charged protons within the nucleus. This imbalance of charge leads to the formation of a negatively charged ion, known as an anion.

In contrast, a cation is formed when an atom loses electrons, resulting in a positive charge. Isotopes refer to variations of the same element that have the same number of protons but a different number of neutrons, thus affecting their mass without altering their ionic charge. The term 'atom' is a general descriptor for the smallest unit of an element, which may be neutral or charged depending on the number of electrons it contains. Therefore, the specific term that describes a negatively charged ion formed by the gain of electrons is anion.