CBSC Science

  Metals and Non- Metals full explaination Class 10 Science Chapter 3 - Metals and non metals Element: Is a substance that can’t be broken into more simpler substances. Elements are classified into different categories: -: Metals :- Metals Metals are those elements which have 1,2 or 3 valence electrons in their valence shell. Example : atomic no. of Na =11 Electronic confugration =2,8,1 They always loose electrons to form electropositive ions. Na – 1electron ------Na + :-  Non Metals :- Non-Metals -> Non metals are those elements which have 4,5,6 or 7 valence electrons in their valence shell and they always gain electrons to form electronegative ions. Cl(17) – 1 electron --------Cl- Electronic Configuration = 2,8,7 Video Explanation of Lesson Metals and Non-Metals II)  Physical Properties Of Metals and Non Metals 1. malleability: process of beating into thin sheets Metals :are malleable. Gold and silver is the most malleable metals. Malleability Non metals :non malle...

Acid-bases and salts * Preparation and uses of important compounds. I) Caustic Soda (Sodium Hydroxide, NaOH) Preparation of Sodium hydroxide Preparation: In the process of electrolytic decomposition of brine (aqueous solution of sodium chloride), brine decomposes to form sodium hydroxide. 2NaCl(aq) + 2H2O(l) → 2NaOH(aq) + Cl2(g) + H2(g) In this process, chlorine is moved towards anode and hydrogen gas is moved towards cathode as by products. This whole process is known as Chlor – Alkali process. Uses: Sodium hydroxide is used for degreasing of metals, manufacturing of paper, soap, detergents, artificial fibres, etc. II) Bleaching Powder (Calcium Oxychloride, CaOCl2) Preparation of Bleaching powder Preparation: Bleaching powder is produced by the action of chlorine on dry slaked lime [Ca(OH)2]. Ca(OH)2 + Cl2→ CaOCl2 + H2O Uses: (i) It is use for bleaching cotton and linen in the textile industry, for bleaching wood pulp in paper factories and for bleaching washed clothes in laundry; (i...