How does the charge of the nucleus differ from the charge of an atom?

An atom's nucleus is the only part that has positive charge; the rest of the atom is made up of the electron cloud, which surrounds the nucleus and has negative charge. Since there are exactly as many electrons as protons in a neutral atom, the atom's net charge is zero.

Atoms can be ionized, which means they have either more or fewer electrons than protons. Positive ions are defined as having fewer electrons, while negative ions are defined as having more electrons. Negative ions are usually unstable and will expel the extra electron, but they can be stable for a while.

The charge of the nucleus is positive, as it contains positively charged protons and neutrally charged neutrons. The charge of an atom as a whole is neutral because it contains an equal number of positively charged protons in the nucleus and negatively charged electrons surrounding the nucleus.