Mass number number of protons in a nucleus, and thus uniquely identifies an element. Hence, the difference between the mass number and the atomic number gives the number of neutrons ("N") in a given nucleus: . The mass number is written either after the element name or as a superscript to the left of an element's symbol. For example, the most common isotope of carbon is carbon-12, or , which has 6 protons and 6 neutrons. The full isotope symbol would also have the atomic number ("Z") as a subscript to the left of the element symbol directly below the mass number:
Atomic spacing frequency through the material, and using the laws of diffraction to determine its atomic spacing. Bond length can be determined between different elements in molecules by using the atomic radii of the atom. Carbon bonds with itself to form two covalent network solids. Diamond's C-C bond has a distance of 0.142 nm away from each carbon, while graphite's C-C bond has a distance of 0.341 nm away from each carbon. Although both bonds are between the same pair of elements they can still have different bond length. Atomic spacing Atomic spacing refers to the distance between the nuclei of atoms