Metal non metal

• Metals:

  • Shining surface in pure state (called metallic lustre)
  • Generally hard
  • Malleable (can be made into thin sheets by beating)
  • Ductile (can be drawn into thin wires)
  • Good conductors of heat
  • High melting point
  • Conduct electricity
  • Produce sound (sonorous)
• Non-metals:

  • Found in all three states at room temperature
  • Iodine (non-metal) has lustre
  • Carbon has allotropes (exists in different forms)
  • Non-metals are soft and have no lustre
  • Non-metals are non-malleable and non-ductile
  • Non-metals are not sonorous
  • Poor conductors of heat and electricity
• Chemical properties:

  • Metals react with oxygen to produce basic metal oxides
  • Non-metals react with oxygen to form acidic non-metallic oxides
• Reaction with oxygen:

  • Metals combine with oxygen to form oxides
  • Most metal oxides are insoluble in water
  • If soluble, they form alkali
  • Some metals like sodium and potassium react easily with oxygen and are kept immersed in kerosene
  • Metals like Mg, Al, Zn, Pb form thin layers of oxides
• Reaction with water:

  • Metals produce metal oxide + H2
  • If oxide is soluble, metal hydroxide is formed
  • Metals like Al, Zn, Fe do not react with water, but react with steam
• Reaction with acids:

  • Metals react with acids to produce metal salts and hydrogen gas
  • Some metals do not react with certain acids like Cu with dilute H2SO4 and dilute HCl
  • Aqua regia can dissolve gold and platinum
• Corrosion:

  • Corrosion is the process of breaking down metals due to reactions with moisture and gases in the air
  • Factors affecting corrosion include reactive nature of metal, presence of dissolved salts, pollutants, and less reactive metals
  • Methods to prevent corrosion include painting, oiling, greasing, galvanization, cathode protection, and alloying
• Alloys:

  • Alloys are homogeneous mixtures of two or more elements, with at least one being a metal
  • Common alloys include stainless steel, brass, and bronze
• Reactivity series:

  • Metals are arranged in decreasing order of electropositive character
  • Metals at the top have greater reducing power
  • Metals at the top show greater tendency to get oxidized
  • Metals above hydrogen liberate hydrogen gas from mineral acids
  • Metals at the top displace metals lower in the series from their salts
• Physical properties of Ionic compounds:

  • Solid
  • Hard
  • Brittle
  • High melting and boiling points
  • Soluble in water; insoluble in kerosene, petrol
  • Conduct electricity in water solution
• Extraction of metals:

  • Methods include roasting, calcination, thermite reaction, and electrolytic reduction
  • Electrolytic refining of metals involves using impure metal as anode and pure metal as cathode with a metal salt electrolyte