C1 Topic 4 - Obtaining and Using Metals Flashcards
Describe what ores and native metals are.
Native metals are found uncombined with other elements. An ore is a metal in a compound with other elements.
Recall the reactivity series.
Potassium K
Describe how metals are extracted from their ores and why different methods are used.
Metals which are less reactive than carbon can be extracted by a reduction reaction which means carbon displaces the less reactive metal. Metals that are more reactive than carbon can’t be extracted by a reduction reaction so they need to be split up with electricity (electrolysis)
Describe oxidation with respect to corrosion of metals.
Oxidation is the gain of oxygen.
Describe reduction with respect to metal extraction.
Metals less reactive than carbon have to be in a reduction reaction with carbon. A reduction reaction is when a metal loses oxygen from its compound.
Explain why iron corrodes and why aluminium doesn’t corrode.
When iron corrodes, it is combining with oxygen and water. The iron gains oxygen to form iron(III) oxide. Water then becomes loosely bonded to the iron(III) oxide so the result is hydrated iron(III) oxide. Aluminium doesn’t corrode because it is corrosion-resistant.
Relate the uses of different metals to their properties.
Aluminium is used for window frames, electricity cables and aircraft because it has a low density and is corrosion-resistant. Copper is used for electrical wires and pipes in plumbing because it is hard, strong and is a good conductor of electricity. Gold is used for jewellery and tooth fillings because is shiny and extremely easy to shape.
Describe what an alloy is and how properties of metals change when they are alloyed.
An alloy is a mixture of two or more metals, or a mixture of a metal and a non-metal. When metals are alloyed they become stronger and more corrosion-resistant.
Describe the uses of different alloys.
Low carbon steel is used for car bodies, high carbon steel is used for blades for cutting tools and bridges and stainless steel is used for cutlery and containers for corrosive substances.
