This heat would have caused any hydrogen present to escape into space. Additionally, the Earth's gravity is not strong enough to hold onto hydrogen gas. Another reason is that hydrogen is a very light element and is easily blown away by the solar wind.
The solar wind is a stream of particles emitted by the Sun. These particles are moving very fast and can easily knock hydrogen atoms out of the Earth's atmosphere.
Lastly, hydrogen is constantly being produced and destroyed in the Earth's atmosphere through a process called the water-gas shift reaction. In this reaction, hydrogen combines with oxygen to form water vapor, which then escapes into space.
The water-gas shift reaction is a chemical reaction that takes place between hydrogen and oxygen. In this reaction, hydrogen combines with oxygen to form water vapor, which then escapes into space.

Chemical Principles (8th Edition)See all exercises

Chemical Principles (8th Edition)