What determines if an atomic particle has a positive, negative, or neutral charge?

The charge of an atomic particle is determined primarily by the number of electrons it contains. Electrons carry a negative charge, and their presence influences whether an atom is neutral, positively charged, or negatively charged. When an atom has an equal number of protons (which have a positive charge) and electrons, it is electrically neutral. If there are more electrons than protons, the atom becomes negatively charged, while having more protons than electrons results in a positively charged atom.

In contrast, neutrons do not carry any charge and thus do not affect the overall charge of the atom. Protons do provide a positive charge, but it's the balance between protons and electrons that ultimately defines whether the atom is neutral or charged. Atomic mass is a measure of the total number of particles in an atom's nucleus (protons and neutrons) and does not influence charge. Therefore, the number of electrons is the correct factor in determining the charge of an atomic particle.