Topic summary
Classical Elements
Extracted from the Wikipedia article Classical element.
Modern science does not support the classical elements to classify types of substances. Atomic theory classifies atoms into more than a hundred chemical elements such as oxygen, iron, and mercury, which may form chemical compounds and mixtures. The modern categories roughly corresponding to the classical elements are the states of matter produced under different temperatures and pressures. Solid, liquid, gas, and plasma share many attributes with the corresponding classical elements of earth, water, air, and fire, but these states describe the similar behaviour of different types of atoms at similar energy levels, not the characteristic behaviour of certain atoms or substances.