Physical Properties Of Metals And Non-Metals

Key Notes :

Physical Properties of Metals

  • Lustre: Metals have a shiny appearance (metallic lustre).
  • Malleability: Metals can be hammered into thin sheets (e.g., aluminum foil).
  • Ductility: Metals can be drawn into thin wires (e.g., copper wires).
  • Conductivity: Metals are good conductors of heat and electricity (e.g., silver, copper).
  • Sonority: Metals produce a ringing sound when struck (sonorous).
  • Hardness: Metals are generally hard (exceptions: sodium and potassium are soft).
  • High Melting and Boiling Points: Most metals have high melting and boiling points (e.g., iron, tungsten).
  • Density: Metals are generally dense (heavy for their size).

Physical Properties of Non-Metals

  • Non-Lustrous: Non-metals are dull in appearance (exceptions: iodine is lustrous).
  • Non-Malleable: Non-metals are brittle and break when hammered.
  • Non-Ductile: Non-metals cannot be drawn into wires.
  • Poor Conductors: Non-metals are poor conductors of heat and electricity (exceptions: graphite conducts electricity).
  • Non-Sonorous: Non-metals do not produce a ringing sound.
  • Softness: Most non-metals are soft (exceptions: diamond is the hardest natural substance).
  • Low Melting and Boiling Points: Non-metals generally have low melting and boiling points.
  • Low Density: Non-metals are less dense compared to metals.

Differences Between Metals and Non-Metals

Practical Applications

  • Metals: Used in construction (iron, steel), electrical wiring (copper), and jewelry (gold, silver).
  • Non-Metals: Used in fertilizers (nitrogen), water purification (chlorine), and as insulators (sulfur, phosphorus).

Exceptions to the Rules

  • Metals like sodium and potassium: Soft and can be cut with a knife.
  • Graphite (a non-metal): Conducts electricity.
  • Mercury (a metal): Liquid at room temperature.

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