Since a nucleus contains protons and neutrons, most of the mass of an atom is concentrated in its nucleus.
It also tells us that chlorine has 18 neutrons (35 - 17) and, as the number of electrons and protons are equal in a neutral atom, chlorine also has 17 electrons. The relative mass of a nucleus is ...
At the cutting-edge Facility for Rare Isotope Beams, researchers have precisely measured the mass of aluminum-22, revealing ...