H2 is the chemical symbol for hydrogen gas, which is a colorless, odorless, and tasteless gas that is lighter than air. Hydrogen is the lightest and simplest element in the universe, and it is estimated to contribute 75% of the mass of the universe. Hydrogen can be found in light, water, air, plants, and even animals, but it is often combined with other chemicals, making it a more familiar scientific combination—H2O, also known as water. Hydrogen is produced by separating it from other elements and collecting the vapor.

Hydrogen gas has many applications, including being used as a critical element for rocket fuel and gas turbines to generate electricity. It is also used in cryogenic research, including superconductivity studies, and as a lifting gas in balloons and airships because it is lighter than air. Hydrogen is a clean alternative to methane, also known as natural gas, and it can be used to power vehicles, generate electricity, power industry, and heat homes and businesses.

Hydrogen is also mentioned as the future primary energy source, and it is considered a promising fuel for road, air, and shipping transportation. Hydrogen can be produced from a variety of resources, such as natural gas, nuclear power, biogas, and renewable power like solar and wind.

In summary, H2 is the chemical symbol for hydrogen gas, which is a colorless, odorless, and tasteless gas that is lighter than air. It is the lightest and simplest element in the universe and has many applications, including being used as rocket fuel, a lifting gas, and a clean alternative to methane.