Hydrogen is the lightest chemical element; it has an atomic number of 8 and an atomic weight of 15,9994. It is also the most abundant chemical element on Earth.
It occurs in a variety of compounds, including water and the many carbon compounds found in plant tissues, animal tissue, and petroleum. Its simplest molecule is water, which contains two hydrogen atoms and one oxygen atom.
A mole of hydrogen has a mass of 2.016 grams. The same mole of oxygen has a mass of 16 grams.
Molecular hydrogen is a gas that forms when two hydrogen atoms bond together. It is a colorless gas at normal temperatures and pressures.
Oxygen is an essential element, as it keeps the human body functioning properly and helps make a variety of substances, including air. It is a colorless gas that makes up 21 percent of the Earth's atmosphere.
The hydrogen atom has two protons and a single electron, while the oxygen atom has eight protons and one electron. The difference in charge between the oxygen and hydrogen atoms gives them the ability to form covalent bonds, which hold molecules together.
Dioxygen is a type of oxygen that forms when a pair of oxygen atoms share a valence electron. It is less reactive than elemental oxygen, which can look for bonds with other elements to fill its outer shells with eight electrons.
It is possible to separate molecular hydrogen into ortho-hydrogen and para-hydrogen using low-temperature gas chromatography, an analytical technique that uses different vapour pressures to distinguish the atoms. This separation process can help scientists understand the difference in physical properties of hydrogen and determine which form may be best for certain applications.
