Ions

Definition
Atoms can readily lose or gain electrons. When a neutral atom loses or gains electrons, it results in an ion. A positively charged ion is a cation, while a negatively charged one is an anion.

Remember: "Cats are nice", hence cations hold a positive charge. Remember: "Onions make you cry", hence anions hold a negative charge.

-An ion consisting of only one atom is referred to as a "monatomic ion"

-When consisting of two or more atoms, it is referred to as a "polyatomic ion"

-Polyatomic ions that contain oxygen are considered "oxyanions" (Ex: Sulfate and Carbonate)

-Ions of opposite charge attract and create ionic bonds

-Common types of chemical bonding occur in the metals and non-metals (Except for noble gases)

-Metals tend to be more electropositive

-Non-Metals tend to be more electronegative

Example
A neutral sodium atom has 11 protons and 11 electrons. If that sodium atom lost 1 electron, it would become an ion with a net charge of +1.

The charge for a chemical symbol is written as a superscript with the sign after the number: