Question

Distinguish between
Physical properties of metals & nonmetals(minimum 4 Points)

Answer 1

Physical properites	Metals	Non-Metals
State	Metals are solids at room temperature. Exception : Mercury (Hg) is a liquid at room temperature.	The non-metals are either solids or gases at room temperature. Exception : Bromine is a liquid at room temperature.
Lustre	Metals are generally lustrous, i.e., they have a shining surface and can be polished, e.g., gold, silver, copper, etc.,	Non-metals generally do not have any lustre, dull in appearance e.g., sulphur and phosphorus Exception : Iodine has a lustrous appearance.
Melting and Boiling Points	Metals have generally high melting Points and boiling points, e.g., the melting point of iron is 1535 0 C. Exceptions : Sodium, potassium and gallium have low melting points. The melting point of gallium is so low that it occurs in liquid state at temperature slightly above room temperature.	Non-metals have low melting points and boiling points. Exceptions : Carbon and silicon, which have high melting points and boiling points.
Density	Metals have high densities, i.e., they are heavy, e.g., the density of mercury is 13.6 gm/cm3 which is quite high. Exceptions : Sodium, potassium, calcium and magnesium which are lightweight metals. Sodium and potassium are so light that they can float on water	Non-metals have low densities. i.e., they are light substances. For example, the density of sulphur is 2g/cm3 which is quite low. Exception: The density of diamond (an allotropic form of carbon) is high
Ductility	Metals are ductile, i.e., they can be drawn into thin wires. Gold and silver are the best ductile metals. Other examples are copper and aluminium which can be drawn into wires and are used in electrical wiring	Non-metals are non-ductile, i.e., they cannot be drawn into thin wires, e.g., sulphur and phosphorus when stretched do not form wires but break into pieces.
Malleability	Metals are generally malleable, i.e., they can be beaten into thin sheets with a hammer,e.g., silver foils are used for decorative purposes on sweets.	Non-metals are not malleable but brittle, i.e., when beaten with a hammer, they break into pieces.
Conduction	Metals are good conductors of heat and electricity. Silver is the best conductor of heat and electricity whereas lead is the poorest conductory of heat. Metals are good conductors of electricity because they contain free electrons to conduct electricity	Non-metals are generally bad conductors of heat and electricity, e.g., the non-metals like sulphur, phosphorus, etc., do not conduct heat and electricity. Exception : Graphite (an allotropic form of carbon) is a good conductor of electricity.
Hardness	Metals are hard (except sodium and potassium which are soft metals) but not brittle. Sodium and potassium are so soft that they can be cut with a knife	Non-metals are generally soft except, diamond (an allotropic form of carbon) which is the hardest substance known.
Sonority	Metals are said to be sonorous, i.e., they make a noise when they are hit with an object	Non-metals are not sonorous.