Summary

Matter is made up of particles and they are atoms, molecules and ions. Any matter that contains particles of only one kind is known as an element.
Examples of elements are gold, silver, oxygen and calcium. Letters are used to represent elements. The letters that is used to represent an element is known as its chemical symbol. The chemical symbol of Oxygen is O.
An ion is an atom or group of atoms which has an electrical charge as a result of gaining or losing one or more electrons.
Ions that are formed when atoms lose electrons to carry positive charges are called cations.
Ions that are formed when atoms gain electrons to carry negative charges are called anions.
Atoms of metals form cations whiles catoms of non-metals form anions.
Atom is the smallest particle of an element but has three smaller particles that make up its structure namely; electrons, protons and neutrons.
Every atom of every element has a particular number of these particles.
For every atom in its neutral state, the number of protons is the same as the number of electrons.
Every atom has its own properties that make it different from other atoms of different kinds or elements.
Some of these properties are their atomic number, mass number, electronic configuration etc.