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SUMMARY – ➢ ➢ ➢ ➢ ➢
History and occurrence of metals. Physical and chemical properties of metals. Extraction of metals (Metallurgy). Process involved during metallurgy of aluminium. Uses and alloys.
SECTION – 1 1.
Write true or false and correct the false statements by changing the underlined words : A) Aluminium foils are used for decorating sweets. B) Oxygen gas is used for hydrogenation of vegetable oils. C) Silicon is used for making microchips. D) Cast iron is the purest form of iron. E) S 2 − is the symbol of sulphide ion since it loses two electrons from its valence shell. F) Gallium is a liquid metal at room temperature. G) Water is an acidic oxide. H) Alkalis are soluble bases.
2.
Name the following : A) The process by which iron ore is concentrated. B) An alloy of iron used for making surgical instruments. C) Two alloys of copper used for making statues. D) A liquid metal and a non-metal. E) Two neutral oxides. F) Two reducing agents. G) The gas evolved when a reactive metal combines chemically with dilute sulphuric acid. H) The products formed when an acidic oxide reacts with a base. I) Two most reactive metals in the metal reactivity series.
3.
Complete and balance the following reactions : A) Na + O₂ → B) K + H₂O → C) Zn + HCl → D) Fe + CuSO₄ → E) CO₂ + NaOH →
4.
Give the composition of the following alloys and state the reason for alloying. (a) Brass (b) Bronze (c) Duralumin (d) Magnalium
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