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Metals
Specification points
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Year 10 Metals
Metallic bonding – recap from year 9
Metals consist of giant structures of atoms arranged in a regular pattern. The electrons in
the outer shell of metal atoms are delocalised and so are free to move through the whole
structure. The sharing of delocalised electrons gives rise to strong metallic bonds. Metallic
bonding is strong so metals have high melting and boiling points. The layers of atoms slide
over each other. This means metals can be bent and shaped.
Properties of transition metals - Comparison with Group 1 elements
Compared with the elements in Group 1, transition elements such as Cr, Mn, Fe, Co, Ni, Cu
• have higher melting points (except for mercury) and higher densities
• are stronger and harder
• are much less reactive and so do not react as vigorously with water or oxygen.
• Many transition elements have ions with different charges, form coloured compounds
and are useful as catalysts.
Metal oxides
Metals react with oxygen to produce metal oxides via oxidation reactions.
Students to explain reduction and oxidation in terms of loss or gain of oxygen.
The reactivity series
The reactivity of a metal is related to its tendency to form positive ions.
The reactivity series eg potassium, sodium, lithium, calcium, magnesium, zinc, iron and
copper can be established by looking at the reactivity with acid and water
Hydrogen and carbon are often included in the reactivity series.
A more reactive metal can displace a less reactive metal from a compound.
Students should be able to:
• Recall. describe the reactions, if any, of potassium, sodium, lithium, calcium,
magnesium, zinc, iron and copper with water (not steam) at room temperature or dilute
acids to produce a reactivity series.
• explain how the reactivity of metals is related to the tendency to form a positive ion
• deduce an order of reactivity of metals based on experimental results.
Extraction of metals and reduction
Unreactive metals such as gold are found in the Earth as the metal itself but most metals
are found as compounds that require chemical reactions to extract the metal.
Metals less reactive than carbon can be extracted from their oxide by reduction/removal of
oxygen with carbon. (Knowledge of processes used in the extraction is not required).
Students should be able to:
• interpret or evaluate specific metal extractions when given appropriate information
• identify the substances which are oxidised or reduced in terms of gain or loss of oxygen.
Oxidation and reduction in terms of electrons
Oxidation is the loss of electrons and reduction is the gain of electrons.
Student should be able to:
• write ionic equations for displacement reactions
• identify in a given reaction, symbol equation or half equation which species are oxidised
and which are reduced.
Alternative methods of extracting metals
The Earth’s resources of metal ores are limited. Copper ores are becoming scarce and new
ways of extracting copper from low-grade ores include phytomining, and bioleaching are
used. These methods avoid traditional mining methods of digging, moving and disposing of
large amounts of rock. Phytomining uses plants to absorb metal compounds. The plants are
harvested and then burned to produce ash that contains the metal compounds.
Bioleaching uses bacteria to produce leachate solutions that contain metal compounds. The
metal compounds can be processed to obtain the metal. For example, copper can be
obtained from solutions of copper compounds by displacement using scrap iron or by
electrolysis. Students should be able to evaluate alternative biological methods of metal
extraction, given appropriate information.
Properties and use of alloys
Most metals in everyday use are alloys. Pure copper, gold, iron and aluminium are too soft
for many uses and so are mixed with other metals to make alloys. The different sizes of
atoms in an alloy distort the layers in the structure, making it more difficult for them to
slide over each other, so alloys are harder than pure metals.
Bronze is an alloy of copper and tin and is used to make statues and decorative objects.
Brass is an alloy of copper and zinc used to make water taps and door fittings.
Gold used as jewellery is usually an alloy with silver, copper and zinc. The proportion of gold
in the alloy is measured in carats. 24 carat is 100% pure gold and 18 carat being 75% gold.
Steels are alloys of iron that contain specific amounts of carbon and other metals. High
carbon steel is strong but brittle. Low carbon steel is softer and more easily shaped. Steels
containing chromium and nickel (stainless steels) are hard and resistant to corrosion.
Aluminium alloys are low density and used in aerospace manufacturing.
Students should be able to interpret and evaluate the composition and uses of alloys other
than those specified given appropriate information.
Independent Study suggestions
1. Look at the specification points above – use the textbook pages (182-207 and 202-207) or the revision
guide pages (112-119) to make a few notes/spider diagram/revision cards
2. Have a go at the questions in the revision guide on pages 120-122 and mark yourself – answers in the
back
3.
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Watch the Fuse School short 3-4 minute explanation videos for any topic where you need more help:
Metallic bonding: https://www.fuseschool.org/topics/66/contents/359
Reactivity series: https://www.fuseschool.org/topics/65/contents/370
Metals and water: https://www.fuseschool.org/topics/65/contents/873
Displacement reactions: https://www.fuseschool.org/topics/65/contents/872
Reactions of copper: https://www.fuseschool.org/topics/65/contents/377
Reactions of iron: https://www.fuseschool.org/topics/65/contents/973
Iron alloys: https://www.fuseschool.org/topics/65/contents/327
Corrosion and rusting: https://www.fuseschool.org/topics/65/contents/367
Rust prevention: https://www.fuseschool.org/topics/65/contents/328
Aluminium extraction: https://www.fuseschool.org/topics/65/contents/1201
Uses of aluminium: https://www.fuseschool.org/topics/65/contents/1050
Recycling metals: https://www.fuseschool.org/topics/65/contents/334
Phytomining: https://www.fuseschool.org/communities/113/contents/946