The hydrogen atom is the simplest of all the atoms and contains one proton and one electron. It is also the first element in the periodic table and the most abundant element in the universe. Hydrogen is a diatom, so in its molecular form it exists with two hydrogen atoms bonded to one another as H2.
It, like all other atoms, consists of two basic parts: the nucleus, where protons and neutrons reside, and the outer portion, where electrons are in continual state of motion in their quantized orbitals. The Hydrogen atom is comprised, most often in nature, of two subatomic constituents: a proton with net positive electric charge, and an electron with a net negative electric charge. Its mass number, usually denoted by A, is one (1) and charge number, denoted by Z, is also one (1). That's why hydrogen is represented as H. Water is a compound of two hydrogen atoms and one oxygen atom.
Hydrogen was discovered by Henry Cavendish in 1776. Antoine Lavoisier gave the element its name and proved that water was made of hydrogen and oxygen.
Name: hydrogen atom
Discovery in: 1776
Density: 0.08988 g/L
Crystal Structure: hexagonal
Melting Point: -259 °C
Boiling Point: -252 °C
Common Uses: hydrogen bombs, hydrogen peroxide, hydrogen fuel