A cation is an ion that has a positive charge, while an anion is an ion that has a negative charge. When an atom or molecule has no charge, it is referred to as being neutrally charged.
When an atom has a neutral charge, it has an equal number of protons, which are positively charged, and electrons, which are negatively charged. An ion occurs when the number of electrons in an atom changes. A cation has a positive charge because it contains more protons than electrons. It loses electrons during reactions with other atoms to which it has given one or more of its electrons. Conversely, an anion has a negative charge because it contains more electrons than protons. It also interacted with other atoms, which gave the atom the added electrons. Elements on the left side of the periodic table of elements are more likely to become cations, while those on the right side are more likely to become anions. This trend is related to the scientific concept of electrovalence. Some examples of cations are chromium(II), written as Cr+2, chromium(III), written as Cr+3, and strontium, written as Sr+2. Anions include cyanide, written as CN-, and chloride, written as Cl-.