* Groups 16 and 17 (chalcogens and halogens): These elements are highly electronegative and tend to gain electrons to achieve a stable octet configuration, forming anions. Examples include oxygen (O²⁻), sulfur (S²⁻), chlorine (Cl⁻), and bromine (Br⁻).
* Groups 13, 14, and 15 (nonmetals): Elements in these groups can also form anions, especially when bonded to more electronegative elements. Examples include nitrogen (N³⁻), phosphorus (P³⁻), and arsenic (As³⁻).
Important Note: Anions are not exclusively found on the right side of the periodic table. Some elements in the transition metals can also form anions, but this is less common.
Remember, an anion is a negatively charged ion, meaning it has gained one or more electrons. The tendency to form anions is related to the electronegativity of an element, which is its ability to attract electrons in a bond.
