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.
Alkaline earth metal The alkaline earth metals are six chemical elements in group 2 of the periodic table. They are beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra).[1] The elements have very similar properties: they are all shiny, silvery-white, somewhat reactive metals at standard temperature and pressure.[2]