Characteristics of metals and non metals

Characteristics of metals and nonmetals

           Metals are generally hard, malleable, ductile, possess lustre and are good conductors of heat and electricity.

      Nonmetals are generally brittle, non-lustrous and are poor conductors of heat and electricity.

          Most of the metals occur in nature in the form of compounds. Only a few metals like gold occur in free state. Nonmetals like nitrogen, hydrogen, carbon and sulphur are formed in elemental form as well as in the form of compounds. And most of the other nonmetals are found in the combined state.

Physical properties of metals and nonmetals

          Let us study the important physical properties of metals and nonmetals.

Physical state

        Metals generally have high melting point. Hence all the metals except mercury exist in the solid state at room temperature. Nonmetals are found in all the three states of matter. carbon, sulphur and phosphorus are solids, bromine is a liquid state while hydrogen, oxygen and helium are gases at room temperature.

Lustre 

         Freshly cut surface pf a metal has a shiny appearance. This property is called metallic lustre. Gold maintain its metallic lustre forever. So it is widely used in making jewels. Nonmetals generally do not have shining surface.

Hardness

           Metals are generally hard and strong. However metals like sodium and potassium are so soft that they can be easily cut with a knife. Nonmetals are generally hard and strong but diamond is the hardest known substance.

Malleability 

           Metals can be beaten into thin sheets and this property is called malleability. Nonmetals are not malleable.

Ductility 

             The property due to which a metal can be drawn into wires is called ductility. This property of metals is used in making electric cables and in making filaments in the electric bulbs. Nonmetals are not ductile.

Conductivity 

            Metals are good conductors of heat and electricity. Gold and silver are the best conductors. Nonmetals are usually non conductors of heat and electricity. But graphite even though a nonmetal is a good conductor of electricity.