physical properties of the element vary depending on the versions - white, red, black and metallic.All other possible represent a mixture of these four or various impurities in them.Modifications differ in many aspects - density, color and other characteristics without a pronounced chemical activity.
White phosphorus - looks very similar to wax and paraffin wax, easy to cut or deformed after very little effort.This modification element is very poorly soluble in water, but well - in organic solvents.The density of white phosphorus is the smallest among all the other versions - 1823 kg / m3, the melting temperature - 44,1oS.Chemically, it
is a little active - is rapidly oxidized in air at room temperature, the consequence of which there is a known glow.
Red phosphorus is obtained by heating at a temperature in white 500 ° C and in an atmosphere of carbon monoxide.It is a polymer with a complex structure, may have different shades of the original color, smaller than that of the white modifications reactivity and extremely low solubility (only in the molten lead or bismuth).In the air or bounce quickly ignited, it has a lower toxicity.By the way, this modification of phosphorus and is used in the manufacture of matches.
Black phosphorus was first brought American physicist Bridgman.Its density - 2690 kg / m3, and it is externally black substance is cast metallic luster very greasy to the touch, somewhat reminiscent of graphite with a fully absent and solubility in water and in solvents.Black phosphorus ignites upon prior raskalivaniya to 400 ° C and under an atmosphere of being in clean air.Melting point - 1000 ° C, the substance has properties of a semiconductor current.
Metal phosphorus is derived latest kind of chemical element with a density of 3.56 g / cm3, and can significantly compacted under increasing pressure, and then also gets the crystal lattice in the form of a cube with the increasing density of up to3.83 g / cm3.It is excellent conductor of electricity.Overall, all modifications have phosphorus chemical activity is much greater than that of nitrogen, which is determined by its allotropic modifications.