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
understand how the crystal structure of metals can explain their physical properties
be able to name some common alloysunderstand why alloys are useful
Physical Properties of some metals (Worksheet)
Metal Symbol Atomic mass
Melting point (C)
State at 25C
Density (g cm–3)
Magnesium 24 650 1.7
Aluminium 27 660 2.7
Iron 56 1535 7.8
Copper 64 1083 8.9
Zinc 65 1500 7.1
Silver 108 961 10.5
Gold 197 1063 19.3
Mercury 201 –39 13.6
Lead 207 327 11.3
Mg
Al
FeCu
Zn
AgAu
HgPb
SolidSolidSolid
Solid
Solid
Solid
Solid
SolidLiquid
3. Why is Mercury an unusual metal?It is the only metal that is liquid at room temp4. List the metals in the table in order of increasing melting points.Hg, Pb, Mg, Al, Ag, Au, Cu, Zn, Fe5. 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, Au7. Which metal has the highest density? Which has the lowest density?Highest: Au, Lowest: Mg8. Is there a general relationship between density and atomic mass?Generally, as the atomic mass increases, the density increases
Use NMS 2 page 52 to complete the table on the worksheet
Metals are This means they
This is used in Which are made of
Sonorous Make a ringing sound when hit
Cymbals in an orchestra
Brass, steel
Lustrous
Malleable
Ductile
Solids with high melting points
Good conductors of heat
Good conductors of electricity
Brainpop
http://www.brainpop.com/science/matterandchemistry/metals/
Metals are This means they
This is used in
Which are made of
Sonorous Make a ringing sound when hit
Cymbals in an orchestra
Brass, steel
Lustrous
Malleable
Ductile
Are shiny
Can be beaten into shape without shattering
Silver, Gold
Mirror/ Jewellery
Car bodies Steel
Can be stretched out to form a wire
Wires Steel
Metals are This means they
This is used in
Which are made of
Solids with high melting points
Good conductors of heat
Good conductors of electricity
Can withstand heat
Heating elements
Nickel alloys
Transmit heat easily
Steel, aluminium, Copper
Pots and pans
Allows electricity to pass through
Electrical wires
Copper
Crystal structure of metals
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
AlloysMixture of metals Have different properties to the original
pure metal from which it was made fromE.g.
Amalgam: mercury with another metal (metal fillings)
Brass (Cu + Zn) – easy to shape
Steel (Fe + C) and Bronze (Cu + Sn) – stronger, resist corrosion
Alloys worksheet - True or false?
1. True2. True3. False: steels are alloys of iron4. False: Bronze contain copper and
tin5. True6. True7. False: Brass is a very hard alloy8. True9. 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 metalsMetal Use Properties
Aluminum Cooking foil 1. Easily rolled into thin sheets.2. Doesn’t melt in the oven.
Gold Jewellery 1. Attractive colour.2. Doesn’t corrode.
Copper Electrical wiring
1. Good conductor of electricity.2. Easily drawn into wires.
Chromium Bathroom fittings
1. Shiny.2. Doesn’t corrode.
Lead Pipes 1. Soft.2. Melts easily.3. Doesn’t corrode.
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.