Metals and Non-metals

Metals- 

In chemistry, a metal is an element that readily forms positive ions (cations) and has metallic bonds. Metals are sometimes described as a lattice of positive ions surrounded by a cloud of delocalized electrons. They are the elements which generally hard malleable, a ductile and good conductor of heat and electricity. Example, silver, copper, mercury etc.

Non-metals- 

Substances which are soft and dull, i.e., non-lustrous, non-sonorous, non-ductile, non-malleable and poor conductor of heat and electricity are called non-metals. They are the elements which are generally soft non-malleable, non-ductile and bad conductor of heat and electricity. For example, oxygen, hydrogen, sulphur, etc.

Metalloids-

 A metalloid is an element that has properties that are intermediate between those of metals and nonmetals. Metalloids can also be called semimetals. On the periodic table, the elements coloured yellow, which generally border the stair-step line, are considered to be metalloids. The elements which show both the character of metals and non-metals are called metalloids. For example- silicon, Germanium(Ge), etc.

Difference between Metals and Non metals

 

Metals	Non-metals
Metals are generally found in solid states, except mercury which is found in the liquid state at ordinary temperature.	They are found in all three states of matter.
Generally, they are hard except alkali metals which can be cut even with a knife.	Generally, they are soft except diamond which is the hardest substance.
They are good conductor of heat and electricity.	Generally, they are bad conductor of heat and electricity except for Graphite which is a good conductor of heat and electricity.
They are malleable and ductile in nature.	There are brittle in nature.
They have a high melting point and boiling point.	Generally, they have low melting point and boiling point except for diamond.