Ammonium dihydrogen phosphate Ammonium dihydrogen phosphate Ammonium dihydrogen phosphate (ADP), commonly called monoammonium phosphate (MAP) is a chemical compound with formula . It is a white crystalline solid consisting of ammonium cations and dihydrogen phosphate anions in equal proportions. ADP is a major ingredient of agricultural fertilizers and some fire extinguishers. It also has significant uses in optics and electronics. Monoammonium phosphate is soluble in water and crystallizes from it as the anhydrous salt in the tetragonal system, as elongated prisms or needles. It is practically insoluble in ethanol. Solid monoammonium phosphate can be considered stable in practice for temperatures up to 200
Caesium oxide Caesium oxide Caesium oxide (IUPAC name) or cesium oxide describes inorganic compounds composed of caesium and oxygen. The following binary (containing only Cs and O) oxides of caesium are known: CsO, CsO, CsO, and CsO. Both the oxide and suboxides are brightly coloured. The species CsO forms yellow-orange hexagonal crystals. Caesium oxide is used in photocathodes to detect infrared signals in devices such as image intensifiers, vacuum photodiodes, photomultipliers, and TV camera tubes L. R. Koller described the first modern photoemissive surface in 1929–30 as a layer of caesium on a layer of caesium oxide on a layer of silver.