Take the tour ×  Silly thought. Feel free to shoot it down  Does
a hydrogen atom undergo any kind of change subject to it's
environment?  If one were to study a hydrogen atom on the
surface of Mercury, another above Earth, and a third in
interstellar space - would they exhibit any difference/s?
share|improve this question add comment  3 Answers  up vote 14
down vote accepted  This is quite far from a silly thought
although this is not apparent at first sight. Apart from a
couple of details which are well understood and have firm
physics behind them - such as the fact that deuterium and
tritium exist in some proportion and the hyperfine-structure
distinction between ortho- and parahydrogen, as far as we can
tell all hydrogen atoms are exactly the same. This is in fact
the case for all atoms and molecules: all iron atoms are exactly
replaceable (so long as you take the right isotope) and nitrogen
molecules are all the same (so long as you take them in the
correct electronic, nuclear and spin states), and so on