Basic questions about hydrogen and hydrogen gas

[Vectronix]

It's been a while since I studied chemistry.

Why are hydrogen atoms always attracted to other hydrogen atoms and then form H₂ (hydrogen gas)?

What are the differences with oxygen binding to itself and the formation of H₂?

 

[Drakkith]

Put simply, it is a less energetic state for the Hydrogen atoms to bind together so that each shares an electron with the other, resulting in a full shell for both atoms. This forms a shell similar to a Helium atom, which is a very stable state. If you look on the periodic table, elements on the left side (the ones under Hydrogen) want to lose an electron to reach the Noble Gas configuration, while everything on the right, next to the noble gases, wants to gain an electron since all it takes is 1 electron for them to reach the noble gas state. Objects in the middle can go either way depending on what they bind with.

 

[Vectronix]

I think the energy level that is required for this 'stability' is different because of the fields from all the other hydrogen atoms, as opposed to a single hydrogen atom isolated in a vacuum. Am I correct about this?

 

[Drakkith]

I think the energy level that is required for this 'stability' is different because of the fields from all the other hydrogen atoms, as opposed to a single hydrogen atom isolated in a vacuum. Am I correct about this?

I don't know what you mean by this. Can you elaborate?

 

[sophiecentaur]

Actually, afaik, Hydrogen atoms traveling very slowly (i.e. at low temperature) are not going fast enough to 'get through' to each other. They will just float around as H atoms. It's only when they hit each other hard enough that they get past the initial electron - electron repulsion that they fall into the lower and more stable energy state of H₂.

You can look upon it in the same way as you look at any chemical reaction. A certain activation energy is needed for the change to take place (e.g. you need to light the fire to start combustion).

 

[Vectronix]

I don't know what you mean by this. Can you elaborate?

Actually, if sophie is indeed correct, then you don't have to worry about what I said previously. :) I just read something last night that explains the relationship between the binding of hydrogen atoms to other hydrogen atoms and the velocity of these atoms. It helped me to understand what she said, and it makes sense. I'll think about what it means in terms of what I said later. :)