Hydrogen is the first element of periodic table
Hydrogen is the chemical element with the symbol H and atomic number is 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula H2 . it is colorless, odoriess, testless, non toxic and highly combustible.
Hydrogen is the most abundant chemical substance in the universe, constituting roughly 75% of all normal matter. Stars such as the are mainly composed of hydrogen in the plasma state. Most of the hydrogen on Earth exists in molecular forms such as water and orhanic compounds. For the most common isotope of hydrogen each atom has one, one electron, and no neutrons.
1 Purple gllow in its plasma state
2 Appearance ; colorless gas
3 Standard atomic weight : 1.007
