Hydrogen is the chemical element with atomic number 1, symbol H At standard temperature and pressure, hydrogen is colorless, odorless, non-metallic, single-valent, and is a highly flammable diatomic gas. With an atomic mass of...

Periodic Table of Elements The Periodic Table of the Elements, also known as the Table or Mendeleev’s Table, or simply Periodic Table, represents all chemical elements, ordered by increasing atomic number and organized according...