© Oxford University Press 2009

7.1 Using Metals

Metals in the periodic table

Most elements are metals

The elements on the left of the stepped line are metals.

© Oxford University Press 2009

7.1 Using Metals

Find 3 essential properties of metals for water pipes

• Malleable

• Do not react with water or air

• Strong

More information:

Lead is no longer used for water pipes because it can make poisonous solutions.

Metal choices…

…copper or lead

© Oxford University Press 2009

7.1 Using Metals

Find 4 essential properties of metals for saucepans

• Good conductors of heat

• Do not react with water

• Malleable

• Strong

Metal choices…

…copper, aluminium or stainless steel

© Oxford University Press 2009

7.1 Using Metals

Find 4 essential properties of metals for jewellery

• Shiny

• Hard

• Malleable

• Do not react with water or air

Metal choices…

…gold, silver, platinum

© Oxford University Press 2009

7.1 Using Metals

Find 3 essential properties of metals for electrical wiring

• Ductile

• Good conductor of electricity

• Do not react with water or air

More information:

Copper is a better conductor than aluminium

Metal choices…

…copper, aluminium

© Oxford University Press 2009

7.1 Using Metals

Find 4 essential properties of metals for long-distance power cables

• Ductile

• Good conductors of electricity

• Low density

• Do not react with water or air

More information:

Copper is 3 times denser than aluminium

Metal choices…

…copper, aluminium

© Oxford University Press 2009

7.1 Using Metals

Find 4 essential properties of metals for aeroplanes

• Low density

• Malleable

• Do not react with water or air

• Strong

More information:

Aluminium does not react with water or air because it forms a protective coating on its surface

Metal choice…

…aluminium

© Oxford University Press 2009

7.1 Using Metals

Find 4 essential properties of metals for light bulb filaments

• Ductile

• Glow when hot

• Very high melting points (so they don’t melt when they glow)

• Good conductor of electricity

More information:

Tungsten has the highest melting point of all metals (3410 ºC)

Metal choice…

…tungsten

© Oxford University Press 2009

7.1 Using Metals

Find 2 essential properties of metals for a tip-over switch

Tip-over switches in electric heaters switch off the current if the heater falls over, so preventing fires.

• Good conductors of electricity

• Liquid at room temperature

More information:

Mercury is the only metal that is liquid at room temperature. Its melting point is -38.9 ºC and its boiling point is 357 ºC

Metal choice…

…mercury

© Oxford University Press 2009

7.1 Using Metals

Find 8 properties that most metals have

• Strong

• Solid at room temperature (melting point above 25 ºC)

• Good conductor of electricity

• Good conductor of heat

• Shiny (at least when first cut)

• Malleable

• Ductile

• Hard

© Oxford University Press 2009

7.1 Using Metals

But metals are not all the same…

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7.1 Using Metals

Extreme metals

Melting points

Highest – tungsten melts at 3410 ºC.

Lowest – mercury melts at -38.9 ºC, so it is liquid at room temperature.

© Oxford University Press 2009

7.1 Using Metals

Extreme metals

Density

Highest – iridium and osmium (22.5 g/cm³)

(lead 11.3 g/cm³)

Lowest – potassium (0.86 g/cm³)

(aluminium 2.70 g/cm³)

So a centimetre cube of iridium weighs 26 times as much as one of potassium!

© Oxford University Press 2009

7.1 Using Metals

Extreme metals

Reactions in water and air

Don’t react at all – platinum and gold

React violently – potassium, rubidium, caesium

© Oxford University Press 2009

7.1 Using Metals

Metal patterns

Different metals have many similarities…

…but many differences

In this unit you will…

• Look at some properties of different metals

• Find patterns in these properties

• Use the patterns to predict metal reactions