Metals and non metals 

Introduction 

Elements can be classified on the basis of similarities and differences in their properties one of the most useful classifications is to categorise the elements as metals and non metals. Elements form both of there categories are used in our day to day life.                        ( Metals and non metals )      A metal is a substance that is hard malleable ductile shiny and sonorous and a good conductor of heat and electricity. Examples of metals are iron lead copper aluminium gold and silver.                                A non metals is a substance that lacks malleable ductile luster sonority and is a poor conductor of heat and electricity. Examples of non metals are graphite diamond sulphur and oxygen.                                    ( Physical properties of metals and non metals.)     

Physical properties are virtues that describe the physical appearance of a substance.   

1*. Physical.                            Almost all metals are solid at room temperature. Mercury and gallium are examples. There metals are liquid at room temperature. All non metals are solid or gases at room temperature. Bromine is an examption. It is liquid at room temperature.                            2.        Hardness                      Metals are hard sodium and potassium are exceptions. They are soft and can be cut with a knife .                     Metals arealleable. Metals like aluminium can be made into thin sheets to be used for various purposes like packing and storing food. Non metals are not malleable. They break into pieces when hammered.       3.  Lustre.                                Lustre is the property by virtue of which a substance shines or glows.                      Metals are shiny and they glow this is the reason why metals like gold and and silver are used to make jewellery non metals lack luster .