# X and Z are two neutral particles. If X donates an electron to Z what is the resulting charge of the two particles?

You exchange 1 electron, the salt would be formulated as ${X}^{+} {Z}^{-}$.
Charge is also fundamentally conserved. When $X$ loses an electron, it becomes ${X}^{+}$, when $Z$ is reduced, i.e. gains an electron, it becomes ${Z}^{-}$. Why can't $X$ or $Z$ lose the positively charged particle to become ${X}^{-}$ and ${Z}^{-}$?