In a hydrogen formula, the gas mainly consists of hydrogen atoms that form diatomic molecules. The molecular formula of hydrogen gas can be established by observing the hydrogen atoms. Typically, a pair of hydrogen atoms are seen to be bonded together into molecules. As a result, the formula is written and expressed as H2.PropertiesValueFormulaH2Density0.0893g/LMolecular weight of hydrogen2.016g/molBoiling Point -252.90CMelting Point -259.20CThe structural representation of the hydrogen chemical formula is given below:H -------- H