The number of electrons that surround the nucleus will determine whether or not an atom is electrically charged or electrically neutral. The amount of charge on a single proton is equal to the amount of charge possessed by a single electron. A proton and an electron have an equal amount but an opposite type of charge. Thus, if an atom contains equal numbers of protons and electrons, the atom is described as being neutral. On the other hand, if an atom has an unequal number of protons and electrons, then the atom is electrically charged. Any particle, whether an atom, molecule or ion, that contains less electrons than protons is said to be positively charged. Any particle that contains more electrons than protons is said to be negatively charged.