held that all matter is made of four elements earth air fire and water
Matter (philosophy) Empedocles held that there are four elements, from which things are derived, Earth, Water, Fire and Air. Some added a fifth element, the Aether, from which the heavens were derived. Socrates accepted (or at least did not reject) that list, as seen from Plato's Timaeus, which identified the five elements with the Platonic solids. Earth was associated with the cube, air with the octahedron, water with the icosahedron, fire with the tetrahedron, and the heavens with the dodecahedron.
Chemical element A chemical element is a species of atoms having the same number of protons in their atomic nuclei (that is, the same atomic number, or Z).[1] 118 elements are identified, of which the first 94 occur naturally on Earth with the remaining 24 being synthetic elements. There are 80 elements that have at least one stable isotope and 38 that have exclusively radionuclides, which decay over time into other elements. Iron is the most abundant element (by mass) making up Earth, while oxygen is the most common element in the Earth's crust.[2]