What are Metals and Non-metals?

  • Elements are classified into Metals, Non-metals and Metalloids

Note :

  • (1) Copper oxide is black in colour.
  • (2) Aluminium oxide is amphoteric oxide.
  • (3) Sodium and potassium react violently with water
  • (4) Magnesium do not react with cold water.
  • (5) Some metals like aluminium, iron and zinc do not react either with cold or hot water.
  • 1. Metals: A substance with high electrical conductivity, lustre and malleability which readily loses electrons to form positive ions.
  • 2. Non-metals: A substance with low electrical conductivity, non-lustrous, non-malleable and which readily gains electrons to form negative ions.
  • 3. Metalloids: Elements with properties intermediate between those of a metal and non-metal.
  • 4. Alloy: A homogenous mixture of a metal with at least one other metal or non-metal.
  • 5. Malleability: It is a physical property of metals that defines the ability to be hammered, pressed, or rolled into thin sheets without breaking.
  • 6. Sonorous: It is the property of a substance to produce a deep resonant sound when collide together.
  • 7. Ductility: It is a physical property of a material associated with their ability to be hammered thin or stretced into a wire without breaking.
  • 8. Ore: A naturally occurring solid material from which a metal or valuable mineral can be extracted profitably.
  • 9. Anion: A negatively charged ion formed by gain of electrons.
  • 10. Cation: A positively charged ion formed by loss of electrons from a neutral atom.
  • 11. Electrodes: An electrode is a solid electric conductor that carries electric current into non-metallic solids, or liquids, or gases, or plasmas, or vacuums.
  • 12. Mineral: A mineral is a naturally occurring solid with a characteristic composition, crystalline atomic structure and distinct physical properties.
  • 13. Smelting: It is a chemical process to isolate an element from its ore using heat and a reducing agent.
  • 14. Gangue: It is an unwanted material or impurities in the form of sand, rock or any other material that surrounds the mineral in an ore deposit.
  • 15. Calcination: The conversion of metals into their oxides as a result of heating to a high temperature in the absence of air or oxygen. The organic matter, moisture, volatile impurities like carbon dioxide and sulphur dioxide are expelled from the ore which makes the ore porous.
  • 16. Roasting: It is a process in metallurgy in which a sulphide ore is heated in air. The process may convert a metal sulphide to a metal oxide or to a free metal.
  • 17. Electroplating: A process that uses electric current to reduce dissolved metal cations so that they form a thin coherent metal coating on an electrode.
  • 18. Galvanisation: A process that applies a coat of zinc to a metal to prevent its oxidation.
  • 19. Refining: It is a method of removing impurities in order to obtain metals of high purity.