Difference between metal and non metals?

Metals and non-metals are differentiated on the basis of its properties.

General Physical Properties of the metals

1) The metals have a shiny appearance, they show a metallic luster. Due to their shiny appearance they can be used in jewellery and decorations. Particularly gold and silver are widely used for jewellery. In the old days, mirrors were made of shiny metals like silver. Silver is a very good reflector. It reflects about 90% of the light falling on it. All modern mirrors contain a thin coating of metals.
Non- metals are dull in appearance except for iodine which shows lusture.

2) Metals are mostly harder to cut. Their hardness varies from one metal to another. Some metals like sodium, potassium and magnesium are easy to cut.
Non-metals have soft surface and can be easily cut except for diamond (carbon) which is the hardest known substance. 
3) Metals on being hammered can be beaten into thinner sheets. This property is called Malleability. Most metals are malleable. Gold and Silver metals are the most malleable metals. They can be hammered into very fine sheets. Thin aluminium foils are widely used for safe wrapping of medicines, chocolates and food material.
non-metals are brittle in nature and break into pieces when hammered.
4) Wires are made from copper, aluminium, iron and magnesium. This property of drawing the metal into thin wires is called ductility. Most metals are ductile.
Being brittle non-metals cannot be drawn into wires.
5) Electric wires in our homes are made of aluminium and copper. They are good conductor of electricity. Electricity flows most easily through gold, silver, copper and aluminium. Gold and silver are used for for electrical contacts in computers. Copper wires are used in electrical appliances while aluminium is cheaper is generally used for making electrical cables.
Non-metals are bad conductors of electricity except graphite (carbon) which is a good conductor of electricity.
6)Cooking utensils and water boilers are also made of iron, copper and aluminum, because they are good conductors of heat.
Non-metals are bad conductors of heat. except for graphite.
7) Metals are generally sonorous. That is they make a ringing sound when struck. Therefore, they are used for making bells. Metal wires are used in musical instruments.
Non-metals are non-sonorous.
8) Metals such as iron are very strong. Therefore, it is therefore, widely used in the construction of buildings, bridges, railway lines, carriages, vehicles and machinery.
Non-metals are brittle.
9) All metals except Mercury, exist in the solid form at room temperature. Therefore, they retain their shapes under normal conditions.

10) Metals have high melting points.
Non-metals have low melting and boling points, (except graphite and diamond)
11) Metals have high tensile strength, that is they can be stretched to some degree without breaking. Metals like tungsten has high tensile strength.
Non metal are brittle. due to low tensile strength.

General Chemical Properties
1) Metals when burned in the presence of oxygen, they combine with oxygen to form metallic oxides which are basic in nature.
Non-metals burn in oxygen to form acidic oxides.

2)Metals differ in their reactivity with acids. Most metals react with acids to produce salts and hydrogen.
Non-metals normally do not react with acids. But some non-metals react with non-metals like sulphur , phosphorus
$HN{O}_3+P\to H_{3}P{O}_4+NO+H_{2}O$
$HN{O}_3+S\to H_{2}S{O}_4+NO+H_{2}O$
$HN{O}_3+Se\to H_{2}Se{O}_3+NO+H_{2}O$
3)Different metals react differently with water. Sodium reacts violently with water forming sodium hydroxide and hydrogen. Magnesium reacts mildly with water but vigorously with steam. Zinc and iron react mildly with steam. Copper, gold and silver do not react with water at all. Most metals, on reacting with water produce hydroxide.

Non-metals generally do not react with water but non-metallic oxides react with water to form acids.