what happens when an atom has no electrons

Hey what do you mean by "an atom breaks apart" ??

The only way for an atom to "break apart" (we call it "disintergrate") is by radioactive decay, which happens when the binding forces is too small to hold the protons and neutrons tight.

loss of e- will simply impose a charge on the atom and the atom is now called an ion.

Because when they become cation or anion,they may have already obeyed the "octet rule' which means their outermost shell has been filled fully.They become very STABLE.
That's why they will intend to lose e+.
So they will break apart easily.

如果atom ionized之後係fill到個orbital full/ half and become very stable and not easy to break apart-_-"