Metals combine with other metals and some non-metallic elements to form a vast number of alloys which enhance the properties of metals in specific applications, e.g., the combination of iron, nickel and chromium provides a series of stainless steel alloys that are in common use. Metals such as nickel, vanadium, molybdenum, cobalt, rare earths and the platinum group metals enable the catalytic reactions for the synthesis of many organic chemicals from petroleum. A wide variety of metal compounds and salts impart beneficial properties to products like plastics in terms of colour, brightness, flame resistance and resistance to degradation. Photography has been made possible by the effect of light on metal salts. Metals are excellent conductors of both heat and electricity.
Thermal conductivity is harnessed in automobile radiators and cooking utensils.
Electrical conductivity provides society with the ability to transmit electricity over long distances to provide lights and power in cities remote from electrical generating stations. The circuitry in household appliances, television sets and computers relies on electrical conductivity. Metals are hard and durable. They are used in applications sensitive to corrosion such as chemical plants, food preparation, medical applications, plumbing and lead in storage batteries. Wear resistance is critical in bearings for all modes of transportation and in machine tools.