Chemical element meaning "no life") for "nitrogen". For purposes of international communication and trade, the official names of the chemical elements both ancient and more recently recognized are decided by the International Union of Pure and Applied Chemistry (IUPAC), which has decided on a sort of international English language, drawing on traditional English names even when an element's chemical symbol is based on a Latin or other traditional word, for example adopting "gold" rather than "aurum" as the name for the 79th element (Au). IUPAC prefers the British spellings "aluminium" and "caesium" over the U.S. spellings "aluminum" and "cesium", and the U.S.
CB military symbol by the United States – signifying crude mustard. In the Second World War the purity of mustard gas was improved through distillation, and this purified chemical warfare agent was designated HD. When it was mixed with a thickener (Agent VV), it was given the symbol HV. Today mustard gas is indicated by the single capital letter H, but HD is still in common use. Military symbols can also reflect the name of where a chemical agent is manufactured. For example, chloropicrin has the symbol PS, which was derived from the British town in which it was manufactured during the First