Allotropes of phosphorus diphosphorus molecule begins to dissociate into atomic phosphorus. P nanorod polymers were isolated from CuI-P complexes using low temperature treatment. Red/brown phosphorus was shown to be stable in air for several weeks and have significantly different properties from red phosphorus. Electron microscopy showed that red/brown phosphorus forms long, parallel nanorods with a diameter between 3.4 Å and 4.7 Å. Allotropes of phosphorus Elemental phosphorus can exist in several allotropes, the most common of which are white and red solids. Solid violet and black allotropes are also known. Gaseous phosphorus exists as diphosphorus and atomic phosphorus. White phosphorus, yellow phosphorus or
Chemical element plants, the calcium in mollusc shells, or the iron in the hemoglobin in vertebrate animals' red blood cells. The concept of an "element" as an undivisible substance has developed through three major historical phases: Classical definitions (such as those of the ancient Greeks), chemical definitions, and atomic definitions. Ancient philosophy posited a set of classical elements to explain observed patterns in nature. These "elements" originally referred to "earth", "water", "air" and "fire" rather than the chemical elements of modern science. The term 'elements' ("stoicheia") was first used by the Greek philosopher Plato in about 360 BCE in his dialogue Timaeus,