The atoms bond because there is a strong enough attraction in both directions and room for the electrons in the outer energy level of the atoms. When two hydrogen atoms and an oxygen atom get close ...
It came when the one electron of the hydrogen atom transitioned from the 2P 1/2 energy level to the 2S 1/2 level. (The leftmost number is the principal quantum number, much like the discrete but ...
One is the spectroscopy of the internal structure, the internal energy levels of the anti-hydrogen atom to compare them ... antihydrogen atoms can make the spectrum narrower," said Hangst.