The Periodic Table

Lithium is a chemical element with the symbol Li and atomic number 3. It is a soft, silvery-white alkali metal under standard conditions,...

Helium (from Greek: Helios,  'Sun') is a chemical element with the symbol  He and atomic number 2. It is a colorless, odorless,...

Hydrogen is the chemical element with the symbol H and atomic number 1. With a standard atomic weight of 1.008, hydrogen is the lightest...