Nitric acid (HNO3) is an extremely important chemical used in the manufacture of fertilisers and explosives. It is made from ammonia by the Ostwald Process (developed in 1902 by the German chemist Wilhelm Ostwald, who got the Nobel prize in 1909).
2. ethics (used with a sing. verb) The study of the general nature of morals and of the specific moral choices to be made by a person; moral philosophy. 3. ethics (used with a sing. or pl. verb) The rules or standards governing the conduct of a person or the members of a profession: medical ethics.
Ethos, a noun, is the fundamental set of beliefs that you, or a society, or group live by. The noun ethos refers to how you, or a group, or a society chooses to live and is the particular rules and characteristic values that organize people. This also means that a different group might have a different ethos.