What is the overall charge of an atom.

Overall, an atom is neutral charged. The Bohr model was for years accepted as the final authority because it agrees so well with experiment and observation. In this model an atom consists of a nucleus containing protons and neutrons. The neutrons are zero charge so we can forget them in looking for charges. For each proton (1 positive charge) there is always 1 electron (1 negative charge) in orbit around the nucleus. thus an atom has a equal number of electrons and protons and their net charge is zero.

We can do things to temporarily up set this natural balance (we call this electricity) but the atoms will eventually return to their naturally balanced state