Uses of Metals
Section: 9. Metals | Syllabus: Cambridge AS Level Physics 9702
Linking Properties to Uses The uses of metals are directly related to their physical and chemical properties . Understanding a metal's properties helps explain why it is chosen for specific applications.
Key Principle When explaining why a metal is used for a particular purpose, always link the metal's properties to the requirements of that use. Copper (Cu) Properties of Copper Excellent electrical conductor (second only to silver) Good thermal conductor Ductile - can be drawn into wires Malleable - can be shaped easily Does not react with water (unreactive) Corrosion resistant (forms protective layer) Uses of Copper Use Property Required Explanation Electrical wires and cables Good electrical conductor, ductile Can be drawn into wires and conducts electricity efficiently with low energy loss Water pipes and plumbing Unreactive with water, malleable Doesn't corrode easily and can be bent into shape for pipes Cooking pans and pots Good thermal conductor Distributes heat evenly for efficient cooking Heat exchangers Good thermal conductor Transfers heat efficiently between fluids Aluminum (Al) Properties of Aluminum Low density (light for a metal) Good electrical conductor Corrosion resistant (forms protective Al₂O₃ layer) Malleable and ductile High strength-to-weight ratio Good thermal conductor Uses of Aluminum Use Property Required Explanation Aircraft construction Low density, strong Lightweight but strong, reduces fuel consumption Overhead power cables Low density, good conductor Lighter than copper, easier to support on pylons Food and drink cans Corrosion resistant, malleable Forms protective layer, doesn't react with food, easily shaped Kitchen foil Malleable, unreactive Can be rolled into thin sheets, safe for food contact Window frames Corrosion resistant, malleable Doesn't rust, can be shaped, low maintenance Car parts (engine blocks) Low density, good thermal conductor Reduces vehicle weight, dissipates heat efficiently Protective Layer Aluminum reacts with oxygen to form a thin layer of aluminum oxide (Al₂O₃) on its surface.
This layer is impermeable and protects the metal underneath from further corrosion. Iron (Fe) and Steel Properties of Iron and Steel Very strong and hard High density High melting point Malleable when hot Magnetic Relatively cheap and abundant Uses of Iron and Steel Use Property Required Explanation Building construction (girders, beams) Very strong, hard Can support heavy loads without bending or breaking Bridges Strong, durable Can bear weight of traffic and withstand stress Car bodies Strong, malleable Can be shaped into panels, provides structural strength Railway tracks Strong, hard, durable Withstands weight and friction from trains Tools (hammers, spanners) Hard, strong Doesn't deform easily under use Machinery and engines Strong, high melting point Withstands high temperatures and mechanical stress Electromagnets Magnetic Can be magnetized and demagnetized easily Steel vs Iron Steel is an alloy of iron with carbon (and sometimes other elements).
It is stronger and more versatile than pure iron, which is why steel is used more commonly in construction and manufacturing. Gold (Au) Properties of Gold Very unreactive (doesn't corrode or tarnish) Excellent electrical conductor Very malleable (most malleable metal) Shiny and attractive High density Uses of Gold Use Property Required Explanation Jewelry Shiny, unreactive, malleable Looks attractive, doesn't tarnish, can be shaped into designs Electronic circuits and connectors Excellent conductor, unreactive Reliable connections that don't corrode over time Dental fillings Unreactive, malleable Safe in the mouth, can be shaped to fit teeth Gold leaf (decoration) Very malleable, shiny Can be beaten into extremely thin sheets Silver (Ag) Properties of Silver Best electrical conductor of all metals Best thermal conductor of all metals Shiny and reflective Malleable and ductile Relatively unreactive Uses of Silver Use Property Required Explanation Jewelry and ornaments Shiny, malleable Attractive appearance, can be crafted into designs Electrical contacts Best electrical conductor Provides most efficient current flow Mirrors Very reflective Reflects light extremely well Photographic film Light-sensitive compounds Silver halides react to light (though digital has replaced this) Zinc (Zn) Properties of Zinc Moderately reactive Corrosion resistant (forms protective layer) More reactive than iron Uses of Zinc Use Property Required Explanation Galvanizing (coating iron/steel) More reactive than iron, corrosion resistant Protects iron from rusting by sacrificial protection Alloys (brass, bronze) Forms useful alloys Brass (Cu + Zn) is strong and attractive Batteries Moderately reactive Used as negative electrode in batteries Galvanizing Galvanizing is coating iron or steel with a layer of zinc.
The zinc corrodes preferentially (sacrificial protection), preventing the iron from rusting. Lead (Pb) Properties of Lead Very high density S…
Interactive revision notes, videos and practice questions load below.