Nitrogen is often referred to as an inert gas, but it is not chemically inert and is used in some inert atmospheres for metalworking and in light bulbs to prevent arcing. It is an essential element in plant and animal life and a component of many useful compounds. Nitrogen combines with many metals to form hard nitrides that can be used as wear-resistant metals. A small amount of nitrogen in steel can inhibit the grain growth at high temperature, and also improve the strength of some steels. It can also be used to create hard surfaces on steel. Nitrogen can be used to produce ammonia, nitric acid, nitrate, cyanide, etc. Manufacture explosives; Filling high temperature thermometer, incandescent bulb; Form inert material to preserve material for use in drying boxes or glove bags. Liquid nitrogen when food is frozen; As a coolant for the lab.