Calcium phosphide Calcium phosphide Calcium phosphide (CP) is the inorganic compound with the formula CaP. It is one of several phosphides of calcium, being described as the salt-like material composed of Ca and P. Other, more exotic calcium phosphides have the formula CaP, CaP, CaP, and CaP. CaP has the appearance of red-brown crystalline powder or grey lumps. Its trade name is Photophor for the incendiary use or Polytanol for the use as rodenticide. It may be formed by reaction of the elements, but it is more commonly prepared by carbothermal reduction of calcium phosphate: The structure of the room temperature form
Calcium coating in moist air, but below 30% relative humidity it may be stored indefinitely at room temperature. Besides the simple oxide CaO, the peroxide CaO can be made by direct oxidation of calcium metal under a high pressure of oxygen, and there is some evidence for a yellow superoxide Ca(O). Calcium hydroxide, Ca(OH), is a strong base, though it is not as strong as the hydroxides of strontium, barium or the alkali metals. All four dihalides of calcium are known. Calcium carbonate (CaCO) and calcium sulfate (CaSO) are particularly abundant minerals. Like strontium and barium, as well as the alkali