Category: Chemistry

Hydrogen (chemical symbol — H, chemical formula — H₂, Latin — hydrogenium) is a chemical element and gas in the first period of D. I. Mendeleev’s periodic table of chemical elements. Atomic number — 1.

What is Oxygen? Oxygen (chemical symbol — O, from the Latin word Oxygenium) — an odorless, tasteless, colorless gas, a chemical element of group 16. Atomic number — 8. Its molecule consists of two atoms (formula O2).