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• Most metals react slowly or not at all with water and often needs to be heated to create conditions to react in
• Calcium, sodium and potassium can react with cold water to form a metal hydroxide and hydrogen:

  • calcium reacts steadily and effervescence is seen as hydrogen is produced
  • sodium floats on water, melts, moves around and fizzes then disappears
  • potassium floats on water, melts, moves around while fizzing, the hydrogen burns and a lilac flame is seen
• Some metals like copper, silver and gold don't react with dilute acids while some like potassium and sodium react violently.

  Most metals react with dilute acids to produce a salt and hydrogen
• A metal will displace a less reactive metal from its salt solution and are also redox reactions as electrons are lost and gained in the same reaction:

  • copper + silver nitrate ---> copper nitrate + silver
  • Cu ---> Cu2+ + 2e- (oxidation)
  • Ag+ + e- ---> Ag (reduction)

  The nitrate ions aren't involved in the reaction and so are spectator ions
• A metal position in the reactivity series compares to carbon indicates how its extracted from its ore and hydrogen shows metal reactivity with dilute acid.

  The more easily a metal atom loses its outer electron and forms a positive ion, the more reactive it will be
• You can determine metal reactivity using water and dilute acid:

  • can show hydrogen forming using burning splint test where the louder the squeaky pop indicates more hydrogen was made - more reactive
  • rate of reaction also seen by the rate effervescence is formed
• Ore - a rock which contains enough metal (highly concentrated metal compound) to make it economically profitable to extract the metal
• Some unreactive metals like gold/platinum are found in the Earth's crust as uncombined elements (mined straight out then usually refined)
• Metals can be extracted by reduction using carbon therefore only metals less reactive can have their oxygen taken in a blast furnace:

  • carbon reduction is cheaper (can act as fuel to provide heat)
• Metals more reactive than carbon have to be extracted by electrolysis of molten compounds so the metal is discharged at the cathode:

  • large amounts of electricity is expensive (costs with melting/dissolving ores)
• Biological methods were developed to extract metals from low-grade ores and waste to prevent shortages despite growing demand:

  • methods are slow as phytoextraction is dependent on weather conditions while bioleaching produces toxic substances (disadvantage)
  • expensive as electrolysis needed to extract metals (disadvantage)
  • smaller damage impact by less pollution and landscape changes (advantage)
  • conserves supplies of high grade ores as bioleaching scrap iron is cheap (advantage)
• Bioleaching - bacteria separates metals and ores by collecting the energy of the bonds so the leachate contains metal ions which can be extracted
• Phytoextraction - plats grow in soil with metal compounds so it builds up in the leaves (can't use/rid metal) which can be harvested, dried then burned in a furnace where the metal in the ashes can be extracted
• Reactions at electrodes during electrolysis are redox reactions as the metal compound is reduces (loses oxygen) and oxidised (gains oxygen) at once

  • iron oxide + carbon ---> iron + carbon dioxide
• Recycling means that used metals can be reduced to manufacture new items in a process including:

  • collecting then transporting used items to a recycling centre
  • breaking up then storing different materials
  • removing impurities from the metals to renew them completely
• Recycling:

  • more economic as less energy is needed to produce a metal (advantage)
  • less damage to the environment as fewer quarries/mines needed (advantage)
  • collection/transport needs organisation, workers, vehicles and fuel (disadvantage)
  • difficult to sort materials (disadvantage)

  Overall, you should recycle as it protects environments (landfill/pollution) , has economic benefits (saves money/provides jobs) and conserves resources/energy (preserve finite or rare materials)
• Life Cycle Assessment (LCA) has 4 stages:

  • Choice of Material - metals have to be mined/extracted which required energy and causes pollution
  • Manufacture - uses energy for products and creates pollution/waste that has to be disposed properly or recycled to be useful
  • Product Use - can damage the environment like how fertilisers damage ecosystems and burning fossil fuels releases greenhouse gases
  • Disposal - usually in landfill sites that can pollute land/water or be incinerated which causes air pollution