What happens to the H electron during acid reaction?

In this generic acid-base reaction:


$\ce{HX + B <=> X- + HB+}$


It's explained that the acid HX donates a proton H+ to its conjugate base HB+. What happens to the electron that was originally in the acid's H atom?




The electron belonging to elemental hydrogen forms part of a covalent bond with $\ce{X}$. In this acid-base reaction the $\ce{HX}$ bond breaks *heterolytically*, meaning that both electrons constituting the bond go to $\ce{X-}$, hence the negative charge.


[![enter image description here](https://i.stack.imgur.com/GKL9M.png)](https://i.stack.imgur.com/GKL9M.png)


The base then donates electrons to the proton, forming the electron deficient species $\ce{HB+}$.


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