Question

What is the difference between two hydrogen atoms, and one hydrogen molecule?

Answer 1

What is the difference between 2 hydrogen atoms and 1 hyrogen molecule?

Explanation:

`H_2 rarr 2H*`

The standard state of elemental hydrogen is as the dihydrogen molecule, `H_2`. We could add energy to the LHS of the equation above and produce two hydrogen atoms as shown. The `H*` radical is a highly reactive species - of course it could react with another `H*` species (to form what), but it could also react with `C-H` or `X-X` bonds to form `C*` and `X*` radicals that continue the chain of reactivity.