SC11 - Obtaining and Using Metals ✓

• Pop Potassium • Stars Sodium • Can Calcium • Make Magnesium • Absolute Aluminium • Crazy (Carbon) • Zillions Zinc • If Iron • Tiny Tin • Little Lead • Children Copper • Spend Silver • Good Gold • Pennies Platinum

• Reacts with cold water to from hydrogen and metal hydroxide • Reacts violently with acid

• Reacts very slowly if at all when with cold water • But reacts with steam to form metal oxide and hydrogen • Reacts with acid to form hydrogen and salt solution

They don’t as they are inert in their pure form.

• A reaction in which a more reactive element displaces a less reactive element from a compound. • e.g. Zn + CuSO4 → ZnSO4 + Cu

A redox reaction as the charge on the metals switch around. e.g. in Zn + CuSO4 -> ZnSO4 + Cu the ionic euation shows that Zn + Cu2+ -> Zn2+ + Cu

• Found uncombined in the earth’s crust. • This applies to elements gold and lower in the reactivity series • Extacted by heating an ore with carbon. • This is for elements less reactive than carbon or else carbon can’t displace it • Electrolysis of molten compound. • This is very expensive so only used for aluminium and upwards as they cannot be ehated with carbon to be extracted

A rock that contains enough of a metal to extract it for a profit.

• Phytoextraction: • Growing plants on lands that contain the desired matal so that they absorb it. • These are then burned and the metal is obtained fromt their ashes • Bioleaching: • Bacteria is grown on low-grade(uneconomical) ore. • This forms a leachate (solution containing the desired metal compound) • The copper is extracted by displacing it with scrap iron.

Pros: • No harmful gases produced • Less landscape damage than mining • Conserves supplies of high grade ores • Doesn’t require high temeratures Cons: • Very slow • Toxic substances can be produced which damage the environment

Pros: • No harmful gases produced • Less landscape damage than mining • Conserves supplies of high grade ores • Can extract minerals from contaminated soils Cons: • Very slow • More expensive than mining some ores • Plant growth is dependant on weather conditions

• Oxidation is the gain of oxygen • Reduction is the loss of oxygen • A redox reaction is a reaction in which a substance is oxidised and another is reduced

When a metal reacts with oxygen (oxidises) making it weaker over time

Rusting occurs when iron/steel reacts with oxygen and water.

They form a protective layer of tarnish stopping any further corrosion

• Natural resources of ores will last longer • Less need to mine and harmful side effects from this • Less pollution from extraction • For many metals this takes less energy • Less waste metals at landfill sites

• Costs of energy is high to collect, transport and sort are high • Sometimes it is more expensive to recycle metals than to extract more

A life cycle assessment is an assessment to work out the environmental impact of the obtaining, manufacturing, use and disposal of a product. It can be used to work out: • Which materials are better to use for manufacturing • Whether its more beneficial to recycle or not