What is hydrogen?

  • Hydrogen is an element; it exists naturally as a molecule. Each hydrogen molecule is made up of two hydrogen atoms.

  • In petrol and diesel cars, the burning of fuel produces carbon dioxide and water. Extra carbon dioxide in the air promotes global warming.

  • In hydrogen cars hydrogen reacts with oxygen in a fuel cell, making electricity to run the car. The only waste product of this process is water vapour.

A short video explaining how hydrogen can be used to fuel cars.

Hydrogen is one of the chemical elements that exist in nature. An element has one type of atom, and it cannot be broken down into other substances. Hydrogen exists naturally as a molecule, consisting of two hydrogen atoms. The chemical formula of hydrogen is H₂.

Most cars burn petrol or diesel in their engines. These chemical reactions make carbon dioxide and water. Carbon dioxide is a greenhouse gas, which means too much of it can promote global warming. Global warming causes climate change, resulting in droughts, floods and extreme weather.

Hydrogen cars help to reduce greenhouse gas emissions. They either burn hydrogen in an engine or they react both hydrogen and oxygen together in a fuel cell. Both processes produce electricity which powers an electric motor. Hydrogen cars produce one harmless exhaust gas – water vapour.

A model of a spinning molecule of hydrogen.