Why different atoms?

[psyguy]

Hi there,

 

So, yes, I did spend some time trying to answer this using google, wiki, and the search feature on this forum, but couldn't find anything that exactly addresses my question.

 

My memory of college chemistry is quite hazy, but if I remember correctly, certain atoms combine in predictable ways to make the same kind of molecule every time. For example, if elemental Hydrogen and elemental Oxygen meet they will make H20 every single time. (If this is wrong, please correct me!).

 

If the above is correct, why doesn't the same logic apply to subatomic particles? If one electron and one proton can combine into a stable, electrically neutral atomic molecule called Hydrogen, why don't they always combine this way? Why do electrons and protons sometimes combine into other electrically neutral atomic molecules? Why do all the other elements exist?

 

Thanks, and sorry for such a basic question. I hope it at least makes sense.

[swansont]

Hi there,

 

So, yes, I did spend some time trying to answer this using google, wiki, and the search feature on this forum, but couldn't find anything that exactly addresses my question.

 

My memory of college chemistry is quite hazy, but if I remember correctly, certain atoms combine in predictable ways to make the same kind of molecule every time. For example, if elemental Hydrogen and elemental Oxygen meet they will make H20 every single time. (If this is wrong, please correct me!).

 

No, it's not this rigid. You can, for example, make hydrogen peroxide: H2O2. Molecules with even more variation are hydrocarbon chains of various lengths; there are lots of ways to combine H and C.

 

If the above is correct, why doesn't the same logic apply to subatomic particles? If one electron and one proton can combine into a stable, electrically neutral atomic molecule called Hydrogen, why don't they always combine this way? Why do electrons and protons sometimes combine into other electrically neutral atomic molecules? Why do all the other elements exist?

 

Thanks, and sorry for such a basic question. I hope it at least makes sense.

 

It boils down to what is energetically allowed and favorable. Hydrogen is formed from protons and electrons, but if they have enough energy, the protons can overcome their repulsion and combine; eventually you get Helium via this process, typically found in stars.

[psyguy]

Thanks! I'm planning to take some physics, chem and bio at a local college in the near future for personal enrichment, but I really wanted the quick-and-dirty answer to this one question in the meantime.