In nuclear science, a pure element is a chemical element that consists of a singular stable isotope – that is, atoms of the same element. Examples of a pure element are gold, aluminium and fluoride.
In chemistry, a pure element is a substance in which all the atoms have the same number of protons or the same atomic number. Chemically pure elements can bond in multiple ways and can be found in a number of structures. For example, carbon can be found as a diamond through the process of pressure and bonding of the carbon elements. Graphite is another example of the layering of carbon isotopes.