Ions form from elements when they gain or loss an electron, causing the number of protons (positively charged) to be unequal to the number of electrons (negatively charged), resulting in a net charge.
If there are more electrons than protons (from an element gaining 1 or more electrons), the ion is negatively charged and is called an anion.
If there are more protons than electrons (via the loss of electrons), the ion is positively charged and is called a cation.
