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Physical properties of metals and their uses. Miss Jan. Physical properties of metals SLOs. understand how the uses of metals are based on their properties Know these terms: electrical conductivity, thermal conductivity, density, ductility, lustre, and malleability
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Physical properties of metals SLOs • understand how the uses of metals are based on their properties • Know these terms: electrical conductivity, thermal conductivity, density, ductility, lustre, and malleability • understand how the crystal structure of metals can explain their physical properties • be able to name some common alloys • understand why alloys are useful
Physical Properties of some metals (Worksheet) Mg Solid Al Solid Solid Fe Cu Solid Zn Solid Ag Solid Au Solid Hg Liquid Pb Solid
3. Why is Mercury an unusual metal? It is the only metal that is liquid at room temp 4. List the metals in the table in order of increasing melting points. Hg, Pb, Mg, Al, Ag, Au, Cu, Zn, Fe 5. Which metal has the lowest melting point? Which has the highest melting point? Lowest: Hg, Highest: Fe
6. List the metals in order of increasing density. Mg, Al, Zn, Fe, Cu, Ag, Pb, Hg, Au 7. Which metal has the highest density? Which has the lowest density? Highest: Au, Lowest: Mg 8. Is there a general relationship between density and atomic mass? Generally, as the atomic mass increases, the density increases
Brainpop • http://www.brainpop.com/science/matterandchemistry/metals/
Are shiny Mirror/ Jewellery Silver, Gold Can be beaten into shape without shattering Car bodies Steel Steel Can be stretched out to form a wire Wires
Can withstand heat Heating elements Nickel alloys Steel, aluminium, Copper Transmit heat easily Pots and pans Allows electricity to pass through Electrical wires Copper
Atoms packed tightly (lattice) • Strong forces between atoms makes metal strong and hard to melt. • Outer electrons (valence e-) free to move about this is how metals conduct heat and electricity • Moving electrons also reflect light lustre
Alloys • Mixture of metals • Have different properties to the original pure metal from which it was made from • E.g. • Amalgam: mercury with another metal (metal fillings)
Steel (Fe + C) and Bronze (Cu + Sn) – stronger, resist corrosion
Alloys worksheet - True or false? • True • True • False: steels are alloys of iron • False: Bronze contain copper and tin • True • True • False: Brass is a very hard alloy • True • False: magnets are made of iron, nickel and cobalt
Photograph of a man sitting on a pool of mercury Mercury is so dense, and clings to itself so strongly, than the man floats on it like styrofoam floats on water.
NMS 2 Page 52-53 1. Uses of metals
2. An alloy is a mixture of two or more metals. 3. Alloys are used because they have more useful combinations of properties than pure metals. 4. See table, p. 53, and the worksheet on alloys.