Earth is made up of many elements that are a product of when the planet's atmosphere was first created billions of years ago. One of these elements is hydrogen, which is one of the least abundant elements on the planet.

Hydrogen is the simplest kind of chemical element and comes first on the periodic table. It has no color, odor or taste, and produces water when it burns in air.

It is impossible to determine exactly how much hydrogen there is on Earth; as it has such a low density, it escapes the planet's gravitational attraction. However, hydrogen exists on Earth in many compounds, such as water, which is actually the most abundant compound on Earth. Hydrogen also exists in almost all organic compounds and makes up about 61 percent of all the atoms in the human body.

Hydrogen could become a future energy source as it can be used to create steam, electricity and other forms of energy. Hydrogen is also considered a clean form of energy, as its only product is water, which is harmless. However, it is also an incredibly unstable element, which makes it dangerous to work with.