The atomic mass of hydrogen is 1.00794 amu (atomic mass units). Its atomic number is 1, and hydrogen has one electron and one proton. This element is a gas at room temperature.
It has a melting point of -434.81 degrees Fahrenheit, and the boiling point is -423.17 degrees Fahrenheit. This element is the most abundant in the universe, and approximately 90 percent of the known universe is made up of hydrogen.
Hydrogen combines with many other elements to produce different compounds like ammonia, water, hydrogen peroxide and methane. Hydrogen does have isotopes, which are protium (H-1), deuterium (H-2) and tritium (H-3). Tritium has a half-life of 12.3 years.