Metals and Non-Metals Class 10 – Important Points

The post Metals and Non-Metals Class 10 – Important Points is about the summary of the whole chapter Metals and Non-Metals Class 10.

• 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 chloride 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.
• Flux is a substance added to the furnace charge to remove non-fusible impurities present in the ore.
• Flux combines with the non-fusible 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 the 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 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).
• The slow destruction of metals by the action of air, carbon dioxide, moisture, etc., is known as the 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
• Gold dissolves in aqua regia. Aqua regia is a mixture of conc. hydrochloric acid and conc. nitric acid in the volume ratio of 3:1.
• Lead on rubbing leaves a mark on the paper. Lead is the poorest conductor of heat.
• When heated with a concentrated solution of sodium hydroxide, Zinc gives off hydrogen gas, while sodium zincate is left in the solution.
• Sulphur is used in the vulcanization of rubber.