The above picture shows the visible light emission spectrum for hydrogen.

The real sticking point is finding economical sources for hydrogen.

Züttel then spent some time going over storage techniques for hydrogen, and they are all pretty bad.

But from the s, p, d, f notation, there is only one energy level for hydrogen.

This reaction has been proposed as a potential source of fuel for hydrogen powered cars.

In other circumstances the pressure balance can be different than it is for hydrogen.

That stands for hydrogen and oxygen, the two components of water.

The energy corridors could also carry pipelines for oil, natural gas, and hydrogen.

Would the Outsider guess that he had a use for partially burnt hydrogen?

It is a potential host for hydrogen in the transition zone of the Earth's mantle.