Elements are the fundamental substances that are made of only one kind of atom. These cannot be any more physically or chemically simplified or decomposed.
- Metals — Small number of Valence Electrons; donates Electrons during Ionic Bonding; forms Cations when ionized. E.g. Potassium
- Non-metals — Valence Electrons are close to completing the Octet Rule. accepts Electrons during Ionic Bonding; forms Anions when ionized; properties are opposite of those of metals; liquid or gas or brittle solids at room temperature. E.g. Oxygen
- Metalloids — Has the physical properties of both metals and non-metals; can act as a metal or a non-metal depending on the conditions. E.g. Silicon (semiconductor)