Materials: Metals and Non-Metals

Quick Revision : Materials: Metals and Non-Metals

• Metals: Shiny, hard, malleable, ductile, sonorous, good conductors of heat/electricity (iron, copper, aluminium).
• Non-Metals: Dull, soft, brittle, non-sonorous, poor conductors (sulphur, carbon, oxygen).
• Malleability: Property of metals to be beaten into thin sheets (aluminium foil, silver foil).
• Ductility: Property of metals to be drawn into wires (copper wires, aluminium wires).
• Sonority: Property of metals to produce ringing sound when struck.
• Chemical Properties: Reaction with oxygen, water, acids, bases, and displacement reactions.
• Metallic Oxides: Basic in nature (turn red litmus blue) - iron oxide, magnesium oxide.
• Non-Metallic Oxides: Acidic in nature (turn blue litmus red) - sulphur dioxide, carbon dioxide.
• Reactivity Series: Arrangement of metals based on reactivity (K, Na, Ca, Mg, Al, Zn, Fe, Pb, H, Cu, Hg, Ag, Au).
• Displacement Reactions: More reactive metal displaces less reactive metal from its compound.
• Reaction with Water: Metals react differently - Na reacts violently, Fe reacts slowly.
• Reaction with Acids: Metals + Acid → Salt + Hydrogen gas (pop sound with burning matchstick).
• Reaction with Bases: Some metals (Al, Zn) react with bases to produce hydrogen gas.
• Uses of Metals: Machinery, electrical wires, cooking utensils, jewellery, construction.
• Uses of Non-Metals: Water purification (chlorine), fertilizers (nitrogen, phosphorus), antiseptics (iodine).
• Exceptions: Mercury (liquid metal), sodium/potassium (soft metals), graphite (conducts electricity).
• Elements: Substances that cannot be broken down further by chemical reactions.
• Atoms: Smallest unit of an element, unaffected by physical changes.
• Metalloids: Elements with properties of both metals and non-metals (silicon, germanium).
• Corrosion: Reaction of metals with moisture/air (rusting of iron, tarnishing of copper).