Important Points of Metals and Non metals

Metals are lustrous, malleable, ductile and have high density.
Metals are generally good conductors of heat and electricity.
Metals form positive ions by losing electrons.
All metals combine with oxygen to form metal oxides.
Metal oxides are basic in nature.
Metals react with chlorine to form electrovalent chlorides of metals.
Metals like Li, Na and Ca form hydrides with hydrogen.
There are metal-bearing substances below the earth’s surface which are called minerals.
The minerals from which metals can be obtained profitably are called ores.
A flux is a substance which is added to the furnace charge to remove nonfusible impurities present in the ore.
Flux combines with the nonfusible impurity to convert it into a fusible substance known as slag.
Nonmetals are generally bad conductors of heat and electricity.
All nonmetals are electronegative.
The function of limestone in the extraction of iron is to provide calcium oxide (CaO) for the formation of the slag CaSiO₃.
Alloy steels are prepared by adding a small quantity of nickel, cobalt, chromium, tungsten, molybdenum, manganese or silicon to steel.
The heating of steel to redness and then cooling it slowly is called tempering of steel.
Rusting of iron is an oxidation reaction which occurs in the presence of air and water.
Aluminium is the most abundant metal in the earth’s crust.
The process of extracting metals from their ores and refining them for use is called metallurgy.
The unwanted materials present in an ore are called gangue.
Froth floatation is a method used for the concentration of some ores.
Calcination is the process of heating an ore strongly so that volatile impurities are removed.
Roasting is the process of heating an ore in a controlled supply of air at a controlled temperature.
Smelting is the process of obtaining metals from their compounds.
Bauxite is an ore from which aluminium metal is commercially obtained.
The most important are of aluminium is bauxite (Al₂O₃× 2H₂O).
Slow destruction of metals by the action of air, carbon dioxide, moisture, etc., is known as corrosion of metals.
An alloy consists of two or more metals, or a metal and a nonmetal. Brass is an alloy of copper and zinc.
The property of an element to exist in two or more ,… different forms is known as allotropy.
The most important ore of copper is copper pyrite (CuFeS₂).
Copper when heated in air at 300°C forms cupric oxide (CuO), while at 1000°C forms cuprous oxide (Cu₂O).
Silver does not react with water and hydrochloric acid. It, however, reacts with nitric acid to produce NO₂ gas.
Gold dissolves in aqua regia. Aqua regia is a mixture of conc. hydrochloric acid and conc. nitric acid in the volume ratio 3 : 1.
Lead on rubbing leaves a mark on paper. Lead is the poorest conductor of heat.
Zinc when heated with a concentrated solution of sodium hydroxide gives off hydrogen gas, while sodium zincate is left in solution.
Sulphur is used in vulcanization of rubber.