Atoms are the building blocks of matter and consist of protons, neutrons, and electrons. Protons and neutrons are located in the atomic nucleus, with protons having a positive charge and neutrons having no charge. Electrons orbit around the nucleus. The atomic number indicates the number of protons in an atom, while the mass number is the total number of protons and neutrons. The atomic mass is the average mass of atoms of that element as found in nature. Sodium atoms have 11 protons, 12 neutrons, and 11 electrons, an atomic number of 11, a mass number of 23, and an atomic mass of approximately 23 amg.
