Write down the various exceptions in physical properties of non metals.
Exceptional Physical properties of non-metals:
(i) Non-metals are generally bad conductor of heat and electricity.
Exception: Graphite being a non- metal is a good conductor of electricity. Non-metals do not conduct the electric current due to absence of free or mobile electrons.
(ii) Non-metals are soft.
Exception: Diamond is hard in nature.
(iii) Non-metals have low melting and boiling points.
Exception: Graphite has very high melting point (3730°C).