white phosphorus P 4 spontaneously reacts with O 2 in the air. reaction equation: P 4 (s) + O 2 (g) P 4 O 10 (s) 5 P 4 combustion in air

Structure of one P 4 simple molecule (white phosphorus) each P atom forms three single covalent bonds to three other P atoms This arrangement forces the bond angles to be less than is favourable and so the structure is under considerable strain – hence the reactivity with O 2

Structure of one P 4 O 10 simple molecule P 4 (s) + 5 O 2 (g) P 4 O 10 (s) For many years this was the main source of phosphoric(V) acid: P 4 O 10 (s) + 6 H 2 O (l) 4 H 3 PO 4 (aq)

One of the most famous alchemical paintings of the eighteenth century. It is by the English painter Joseph Wright ( ). The full title is : "The Alchemist in Search of the Philosopher's Stone Discovers Phosphorus and Prays for the Successful Conclusion of his Operation, as was the Custom of the Ancient Chemical Astrologers." The Discovery of Phosphorus as painted by Joseph Wright

in 1669, Hennig Brand, a Hamburg alchemist, like most chemists of his day, was trying to make gold. The first recipe for phosphorus reaction equations: 1.(NH 4 )NaHPO 4 NaPO 3 + NH 3 + H 2 O He let urine stand for days in a tub until it putrified. Then he boiled it down to a paste, heated this paste to a high temperature, and drew the vapours into water where they could condense - he hoped to gold. To his disappointment he obtained instead a white, waxy substance that glowed in the dark… 2.8 NaPO C 2 Na 4 P 2 O CO + P 4 P 4 is highly corrosive (causing very painful skin damage) and toxic (about 0.05g can be a lethal dose). hence phosphorescence

USS Alabama hit by a white phosphorus bomb in a test in September P 4 as a weapon

RAF fire bombing of Hamburg. The use of phosphorus incendiary bombs contributed to the creation of a fire storm. 40,000 people were killed. P 4 as a weapon

White phosphorus bombs are still being used. The US military often employed them as antipersonnel weapons during the Iraqi conflicts. P 4 as a weapon

A Biography of the Devils Element An excellent book about phosphorus by John Emsley. The cover illustration relates to the earliest matches. These made use of red phosphorus, a more stable form of the element than white phosphorus, P 4