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Class 8 Chemistry: Chapter 6 Materials Around Us: Metals and Non-Metals (Curiosity New Syllabus) | 1. Classification of Elements Elements are categorized based on their physical and chemical properties. Under the new curriculum, we focus on how these materials behave in our daily environment. Key Terms: + Malleability: The property by which materials can be beaten into thin sheets. * Ductility: The property by which materials can be drawn into wires. * Sonority: The ability of a material to produce a ringing sound when struck. | 2. Physical Properties Property | mete | Nonetas | Appearance Lustrous (Shiny) Dull (Except Iodine) Physical Stee Generally Solids (Except Mercury) Solids, Liquids, or Gases _ . Poor conductors (Except Conductivity Good conductors of Heat & Electricity . Graphite) Generally Hard (Except Sodium & Potassium) Hardness Generally Soft (Except Diamond) | 3. Chemical Properties A. Reaction with Oxygen Metals react with oxygen to form Basic Oxides. For example, when magnesium burns in air, it forms Magnesium Oxide (MgO). Non-metals react with oxygen to form Acidic Oxides. For example, sulphur reacts with oxygen to form Sulphur Dioxide (SO;). B. Reaction with Water Metals like Sodium react vigorously with water, while others like Iron react slowly. Most non-metals do not react with water, which is why phosphorus is stored in water to prevent contact with air. DISPLACEMENT REACTION Amore reactive metal displaces a less reactive metal from its salt solution. Example: Iron + Copper Sulphate > Iron Sulphate + Copper (The blue color of Copper Sulphate fades as red-brown copper is deposited). | 4. Uses of Metals and Non-Metals « Metals: Used in making machinery, automobiles, satellites, and cooking utensils due to strength and conductivity. + Non-Metals: ° Oxygen: Essential for respiration. ¢ Nitrogen: Used in fertilisers to enhance plant growth. e Chlorine: Used in water purification. ° Iodine: Used as an antiseptic (purple solution). Study Notes | Curiosity Series | Class 8 Chemistry 
