The number of electrons determines charge and the number of neutrons determines mass of the atom.
Work Step by Step
The number and arrangement of electrons in an tom determines the charge of the atom. If an electron is lost , the atom has a positive charge and if an electron is gained by the atom, the atom has a negative charge. The number of neutrons along with protons determine the mass of the atom. Besides this, the number of neutrons in an atom also determines the isotopes.