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Metals and non-metals||class 10 science lesson 3 notes

  Elements are classified as metals and non-metals.  Metals are mostly solids, lustrous, have high density, good conductor of heat and electricity, malleable, ductile and tenacious.  Mercury is a liquid metal.  Metals lose electrons to form cations.  Non-metals  usually have properties contrary to metals. They usually form acidic oxides.  Metals activity series K>Na>Ca>Mg>Al>Zn>Fe>Pb>[H]>Cu>Hg>Ag>Pt>Au. 1) metals below hydrogen cannot displace hydrogen from acids.  2) metals above hydrogen can displace it from dilute acids.  3) The higher the position, the more active is the metals.  Minerals from which metals may be extracted economically are called ores.  Heating of ore in the presence of air is called roasting.  Heating of ore in the absence of air is called calcination.  The process of reducing the roasted ore is called smelting.  Refining of metals can be carried by distilla...