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GCSE Science A Scheme of Work

Unit 2 – Chemistry 1This scheme of work suggests possible teaching and learning activities for each section of the specification. There are far more activities suggested than it would be possible to teach. It is intended that teachers should select activities appropriate to their candidates and the curriculum time available. The first two columns summarise the specification references, whilst the Learning Outcomes indicate what most candidates should be able to achieve after the work is completed. The Resources column indicates resources commonly available to schools, and other references that may be helpful. Higher Tier material is indicated by a bold HT only comment. The timings are only suggested *, as are the Possible Teaching and Learning activities, which include references to experimental work and How Science Works opportunities. Resources are only given in brief and risk assessments should be carried out.

Most centres will have access to a Virtual Learning Environment (VLE), and Key Stage 4 related science materials. In the resources, reference is made to VLE and interactive software. Most VLE software providers have similar presentations on the topics. Before using any presentation, teachers are reminded that they should decide in advance which slides are most suitable to achieve the learning objectives and edit the presentation accordingly before the lesson.

To access classroom activities, practical ideas, progress checks / end of topic assessments and over 200 questions and mark schemes for Chemistry Unit 1, use Exampro Extra Online, our FREE resource for AQA teachers.*The suggested timings relate to the learning outcomes rather than to the activities.

Throughout this unit candidates will be expected to write word equations for reactions specified. Higher Tier candidates will also be expected to write and balance symbol equations for reactions specified throughout the unit.

C1.1.Fundamental Ideas in Chemistry Atoms and elements are the building blocks of chemistry. Atoms contain protons, neutrons and electrons. When elements react they produce compounds.

Spec Reference

Summary of the Specification Content

Learning Outcomes What most Candidates should be able to do

Suggested timing

(lessons)

Possible teaching and Learning Activities Homework

Resource Examination ‘hints and tips’Candidates should:

C1.1.1 Atoms

a All substances are made of atoms.

Know that substances are made of atoms. State that

1 Activity: Use the Periodic table to elicit answers about:

Periodic table/ data sheet for chemistry

Be able to use symbols

Version 1.0 1 Copyright © 2011 AQA and its licensors. All rights reserved


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b

c

d

Atoms are represented by symbols.

Atoms have a small central nucleus, of protons and neutrons, surrounded by electrons.

The relative electrical charges are as shown:

Proton – charge of +1Neutron – no chargeElectron – charge of -1Two of these particles are charged.

substances made of only one sort of atom are called elements.

Know that elements are found in the periodic table and that groups contain elements with similar properties. State where metals and non-metals appear in the Periodic table.

Know that symbols represent atoms of different elements.

Know the structure of an atom.

Know the charges on sub-atomic particles.

Use the periodic table to work out the number of each type of sub-atomic particle for a named atom.

list of known elements (about 100) location of non-metals and metals groups and periods idea of atoms. use of symbols and rules for their

use proton number, mass number.

Task: Candidates make notes on their Data sheet for the Periodic table, and in books.

Task: Candidates view/draw diagrams of basic atomic structure naming sub-atomic particles.

Discuss: charges on sub-atomic particles, and produce chart in books. How Science Works: Drawing a table.

Task: Work out number of electrons, protons and neutrons in first ten elements of Periodic table. Results as

Information about the Periodic table can be found on the BBC website at www.bbc.co.uk/learningzone/clips by searching for clip ’4406’.

VLE/Interactive software eg periodic table slides.

VLE/Interactive software eg The Atom.

View the Atomic structure PowerPoint presentation at www.iteachbio.com/Chemistry/Chemistry/Atomic%20Structure.ppt

confidently.

Be able to calculate numbers of protons, neutrons, and electrons in an atom, using the Periodic table.

Know the difference between atomic number and mass number.


http://www.iteachbio.com/Chemistry/Chemistry/Atomic%20Structure.ppt



http://www.bbc.co.uk/learningzone/clips



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e

f

g

In an atom, the number of electrons is equal to the number of protons in the nucleus. Atoms have no overall electrical charge.

All atoms of a particular element have the same number of protons. Atoms of different elements have different numbers of protons.

The number of protons in an atom of an element is its atomic number. The sum of the protons and neutrons in an atom is its mass number.

diagrams or chart in books.

Homework: Candidates draw structures of several named atoms using the periodic table.

h Electrons occupy particular energy levels. Each electron in an atom is at a particular energy level (in a particular shell).

Describe electron arrangements for elements up to number 20.

1 Review atomic structure, nucleus and electron cloud.

Explain: Introduce idea of shells within the cloud, and filling numbers and order. Use electron shell sheet to

Electron shell diagram sheet with elements placed in same position as Periodic table, elements 1 – 20.

VLE/Interactive software eg



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The electrons in an atom occupy the lowest available energy levels (innermost available shells).

complete them. Teacher complete elements 1,2,3,7 and 11, candidates complete others.

You may wish to flag up the electronic structure of the noble gases prior to next lesson (continuity point).

periodic table slides.

View the electron shell PowerPoint presentation at http://education.jlab.org/jsat/powerpoint/chembond.ppt

Note: They do not have full outer shells, except for He

and Ne. From Ne onwards they have eight electrons in their outer shell.

C1.1.2 The periodic table

a

b

Elements in the same group in the periodic table have the same number of electrons in their highest energy level (outer electrons) and this gives them similar chemical properties.

The elements in Group 0 of the periodic table are called the noble gases. They are unreactive because their atoms have stable arrangements of electrons.

Know that elements in the same group have similar reactions because they have identical numbers of outer electrons.

Know that the number of outer electrons determines how an atom reacts. Atoms with eight electrons in their outer shell are unreactive, i.e. the noble gases.

Know that noble gases have eight outer electrons except for

1 Demo: Li, Na and K with water. Show H2 gas produced and alkali solution as well.

Task: Candidates describe tests and write word equations for the reactions.

How Science Works: Making a prediction. Ask candidates what they think reaction of Caesium (Cs) would be, show video clip of reaction with water.

Demo: Burning Li, Na and K in air to react with oxygen.

Large glass troughuniversal indicator small pieces ( rice grain) of alkali metals Li, Na, K,forceps,paper towels,scalpel,safety screen,glass tube (8mm wide), splints and matches.

Note: Candidates are not required to know of trends within eachgroup in the periodic table.

Be aware ofsimilarities between the elements within a group.


http://education.jlab.org/jsat/powerpoint/chembond.ppt



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helium, which has two.

C1.1.3 Chemical reactions

b Chemical reactions can be represented by wordequations

Write word equations to represent reactions.

1 Task: Candidates write one word equation to show general reaction.

Mention the outer electrons are causing the reactions.

Note: Indicate that noble gases, except for helium, have eight electrons in their outer shells and therefore are unreactive. Candidates make notes.

Homework: Explain why noble gases do react with other elements to make compounds. Candidates should draw diagrams to show the electrons in at least three different elements.

VLE / Interactive software eg Alkali Metals slides.

View the Alkali metals video on the BBC website at www.bbc.co.uk/learningzone/clips by searching for clip’4407’

You can find a variety of resources including video clips on the RSC website at www.rsc.org/education/teachers/resources

Multi-media science school for Cs demo video.

Be able to write word equations for reactions in the specification.

Chemical reactions can be represented by word equations or by symbol equations.

Know how to represent a chemical reaction by using a word equation.

HT only

1 Review idea of word equation and introduce symbol equations.

Explain: Show need for balancing the equation linked to idea of conservation

VLE/Interactive software eg chemical reactions.


http://www.rsc.org/education/teachers/resources

http://www.rsc.org/education/teachers/resources




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Balance a given symbol equation.

of mass.

Task: Candidates to balance several equations themselves.

a When elements react, their atoms join with other atoms to form compounds. This involves giving, takingor sharing electrons to form ions or molecules.

Compounds formed from metals and non-metals consist of ions.

Compounds formed from non-metals consist of molecules. In molecules the atoms are held together by covalent bonds.

Describe the electron arrangements of sodium and chlorine.

Describe how an electron is transferred to chlorine from sodium to form two charged particles called ions that attract each other.

Know that compounds made from a metal and a non-metal are made from ions.

Know that non-metal compounds are made from molecules, held together by covalent bonds.

1 Review Group 1 and water reactions, ‘what has happened? ‘.

Video/Demo: Show video clip or demonstrate sodium burning in chlorine to make sodium chloride.

Suggest electron transfer to explain bonding and change in properties, and idea of ions.

Task: Candidates make notes/diagrams of electron transfer to show the formation of ions, and electrostatic attraction.

Homework: Candidates work out what happens in another Group 1 and 7 reaction, eg KF.

More information can be found on the BBC GCSE Bitesize – Chemistry at www.bbc.co.uk/schools/gcsebitesize.

A video on alkali metals can be found on the BBC website at www.bbc.co.uk/learningzone/clips by searching for clip ‘4407’.

You can find a variety of resources including video clips on the website at www.rsc.org/education/teachers/resources/alchemy/index.htm

Gas jar chlorine, deflagrating spoon, small piece of sodium, Bunsen burner, and

Note: Further details of the types ofbonding are not required.

Know thatmetals lose electrons to form positive ions, whereas non-metals gain electrons to form negative ions.

Know that such transfers are limited to single electrons.


http://www.rsc.org/education/teachers/resources/alchemy/index.htm





http://www.bbc.co.uk/schools/gcsebitesize



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fume cupboard.

VLE/Interactive software, eg bonding.

View the bonding PowerPoint presentation at http://education.jlab.org/jsat/powerpoint/chembond.ppt

c No atoms are lost or made during a chemical reactionso the mass of the products equals the mass of the reactants.

Know that all atoms involved in a reaction must be accounted for.

Calculate the amount of a product or reactant from masses of other products and reactants (the use of relative atomic masses and relative molecular masses is not needed here).

HT onlyUnderstand symbol equations, balance symbol equations.

1 Tasks: Candidates carry out and report precipitation reaction experiments such as lead nitrate and potassium iodide to observe there is no change in mass on forming products.How Science Works: Write method/plan of practical.Use word equations to describe reactions. Higher Tier candidates should be able to balance given symbol equations (if balancing lesson already completed, if not use in next lesson).

Homework: Candidates do calculations using mass of reactants and products to find mass formed of one product or mass needed of one

Balances, boiling tubes, 25cm3 measuring cylinders, lead nitrate solution 1mol dm-

3 potassium iodide 1 mol dm-3

Be able to calculatethe mass of a reactant orproduct from informationabout the masses of theother reactants and products in the reaction.





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reactant.



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C1.2 Limestone and Building Materials. Rocks provide essential building materials. Limestone is a naturally-occurring resource that provides a starting point for the manufacture of cement and concrete.

C1.2.1 Calcium carbonate

a

b

d

Limestone, mainly composed of the compoundcalcium carbonate (CaCO3), is quarried and can be used as a building material.

Calcium carbonate can be decomposed by heating (thermal decomposition) to make calcium oxide and carbon dioxide.

Calcium oxide reacts with water to produce calcium hydroxide, which is an alkali that can be used in the neutralisation of acids.

Know that limestone is calcium carbonate and that it is quarried.

Know that, when heated limestone becomes calcium oxide giving off carbon dioxide.

Know that calcium oxide reacts with water to make calcium hydroxide.

Know that:

2/3 Activity: Candidates carry out decomposition of limestone to make limewater. Steps:

1. Heat limestone strongly.2. Take calcium oxide formed and

dissolve in water.3. Filter

4. Evaporate to show calcium hydroxide, re-dissolve and filter (optional step).

5. Blow exhaled air (carbon dioxide) through the solution (limewater), making calcium carbonate.

6. Test for carbon dioxide.

Discuss and make flow chart to show word equations for reactions involved.

HT only Could balance symbol equations if

VLE/Interactive software eg useful Materials from rocks.

Exampro Extra Online Practical Guide – Chemistry of the Limestone Cycle.

View the limestone uses PowerPoint presentation at www.worldofteaching.com/powerpoints/chemistry/Limestone.ppt

Note: Knowledge of the commonnames quicklime and slakedlime is not required.

Be familiarwith using limewater to testfor carbon dioxide gas.


http://www.worldofteaching.com/powerpoints/chemistry/Limestone.ppt




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e A solution of calcium hydroxide in water (limewater) reacts with carbon dioxide to produce calcium carbonate. Limewater is used as a test for carbon dioxide. Carbon dioxide turns limewater cloudy.

calcium hydroxide is an alkali that neutralises acids

calcium hydroxide dissolves in water to make a solution called limewater

limewater reacts with carbon dioxide to make calcium carbonate

this reaction is a test for carbon dioxide as the solution goes cloudy.

given them.Limestone/marble chips, matches and spills, watch glass, filter funnel, filter paper, 100 cm3 conical flask, evaporating basin, boiling tube and clean straw.

c

f

The carbonates of magnesium, copper, zinc, calcium and sodium decompose on heating in a similar way.

Carbonates react with acids to produce carbon dioxide, a salt and water. Limestone is damaged by acid rain.

Know that:

metal carbonates decompose on heating to give carbon dioxide and the metal oxide

metal carbonates react with acids to produce carbon dioxide

limestone is damaged by acid rain.

1 Activity: Test each carbonate with acid to see that it evolves carbon dioxide gas, and then dry carbonates are heated to decompose.

Use only Mg, Cu, Zn, Ca, and Na carbonates.

Homework/ How Science Works: Give candidates five samples of rock ores each containing different amounts of copper carbonate. They use today’s practical to help them plan an investigation to determine which ore is most likely to contain the most copper carbonate.

Mg, Cu, Zn, Ca, Na, carbonates. Dilute hydrochloric acid, test tubes, boiling tubes with delivery tubes, clamps and stands, matches and spills and limewater.

Note: Not all carbonates ofmetals in Group 1 of the periodic table decompose at the temperatures reached by a Bunsen burner.



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Know that limestone is needed for buildings and that the positive benefits of using this material should be considered against the negative aspects of quarrying.

1 Research: Candidates can research the impact of limestone quarrying on a community.

Task: Devise role play or use the one from Salters’ Chemistry on plans for a new limestone quarry.

Salters’ Chemistry role play.

VLE/Interactive software, eg useful materials from rocks.

More information about the impact of quarrying can be found at www.slideshare.net/cheergalsal/quarrying-378547


http://www.slideshare.net/cheergalsal/quarrying-378547

http://www.slideshare.net/cheergalsal/quarrying-378547


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g Limestone is heated with clay to make cement.Cement is mixed with sand to make mortar and with sand and aggregate to make concrete.

Explain the differences in the making and composition of cement, mortar and concrete.

1/2 Research: Candidates research the differences between cement, mortar, and concrete, and produce a mini-project on them as building materials.

Alternatively, candidates prepare samples of each as beams and test their strength to breaking point (2 lessons).

Homework: Worksheet on using different building materials for different uses.

Powdered cement, sand, margarine tubs or similar to act as moulds, pea gravel, plastic cups/beakers/buckets to mix in and wooden rods to stir mixture with.

Be able to explain clearly how differences in the properties of named building materials affect their use as building materials.

C1.3 Metals Metals are very useful in our everyday lives. Ores are naturally-occurring rocks that provide an economic starting point for the manufacture of metals. Iron ore is used to make iron and steel. Copper can be easily extracted but copper-rich ores are becoming scarce so new methods of extracting copper are being developed. Aluminium and titanium are useful metals but are expensive to produce. Metals can be mixed together to make alloys.

C1.3.1 Extracting metals

a Ores contain enough metal to make it economical to extract the metal. The economics of

Explain how an ore is different from a rock.

2 Discuss: Teacher-discussion on making metals, ores, gold and silver etc. Discuss and relate extraction methods to limestone quarrying, and talk about metal recycling to reduce

VLE/Interactive software, eg useful materials from metal ores.



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b

c

extraction may change over time.

Ores are mined and may be concentrated before the metal is extracted and purified.

Unreactive metals such as gold are found in the Earth as the metal itself but most metals are found in compounds that require chemical reactions to extract the metal.

Know that methods may be used to concentrate an ore before extraction.

Know that some metals are so unreactive they can be found as metal in the earth’s surface (crust).

impact of quarrying and economic considerations.

Demo: Ag, Cu and Au in hydrochloric acid to show unreactive nature of these metals.

Task: Candidates make brief notes in books.

Activity: Concentrating an ore – heat a small quantity of copper carbonate until it stops ‘bubbling’ and has turned black. Candidates could weigh the sample before and after heating to work out mass lost of carbon dioxide (refer back to lesson on heating carbonates and suggested homework task).

How Science Works: 1. Candidates to compare each

others’ results.2. Plot graph of class results of

mass used against mass lost,3. Mention variables are

continuous.4. Identify range of data.5. Describe relationship between

Copper carbonate, matches and spills, boiling tubes, boiling tube holders( or clamp and stand) mineral/glass wool plug for boiling tube.



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mass used and mass lost.

Candidates are to keep their copper oxide for next lesson.

Homework: Explain the benefits a company can gain by concentrating a metal ore before refining it.

d Metals that are less reactive than carbon can be extracted from their oxides by reduction with carbon,for example iron oxide is reduced in the blast furnace to make iron.

Know that:

metals below carbon in the reactivity series are extracted by heating the oxide with carbon

coke ,charcoal and wood are all good sources of carbon

removal of oxygen from a compound is reduction.

By using the Reactivity Series the method of extraction of a named metal.

1 How Science Works: The first samples of copper man made were found in camp fires. Thinking about what a camp fire has in it, ask candidates guess what happened, to make a hypothesis about the guess, how could they test their hypothesis, and predict what should happen if they test their guess.

Explain: about wood/charcoal/stones containing copper ores, and heat. Use Chemistry data sheet to find position of carbon and copper in reactivity series.

Task: Candidates then heat their copper oxide from last lesson with carbon/charcoal to see if they can make copper (tip heated mixture into cold water to prevent copper re-

Chemistry data sheet.

VLE /Interactive software, eg useful materials from metal ores.

Copper oxide, carbon, or wooden spill, matches and spills, boiling tubes, boiling tube holders, or clamp and stand, mineral/glass wool plug for boiling tube and 250 cm3 beaker of cold water.

Be able to find a metal’s position in both the periodic table and the reactivity series, when given a metal to extract in an examination question, and be able to predict the best method of extraction – carbon or electrolysis.



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oxidising back to copper oxide).

Conclude with idea that the carbon has removed the oxygen from the metal oxide and that removal of oxygen is ‘reduction’. This is how iron oxide is turned in a blast furnace into iron. Details are not required, although it may make interesting homework.

Demo: Blast furnace using potassium permanganate, iron oxide, and carbon with a mineral wool plug. Test iron made with a magnet.

Homework: Report the experiment candidates did.

See resources on Exampro Extra Online for this.

f Copper can be extracted from copper-rich ores by heating the ores in a furnace (smelting). The copper can be purified by electrolysis. The supply of copper rich ores is limited.

Know that:

copper is initially reduced in a furnace with carbon

it is purified by electrolysis copper ores are finite.

1/2 Task: Candidates review/ investigate how copper is mined, extracted and purified by electrolysis.

Candidates should make brief notes/flow diagram on basics of extraction, by copper ore heated in furnace, impure copper dissolved in sulfuric acid, followed by electrolysis.

Demo: Electrolysis of copper sulfate

RSC Alchemy has section on Copper refining which can be found at www.rsc.org/Education/Teachers/Resources/Alchemy/index.htm

VLE/Interactive software, eg useful materials from metal

Note: there is no need to learn extraction processes for individual metals, only how to decide on the extraction process.


http://www.rsc.org/Education/Teachers/Resources/Alchemy/index.htm




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e Metals that are more reactive than carbon, such as aluminium, are extracted by electrolysis of molten compounds. The use of large amounts of energy in the extraction of these metals makes them expensive.

solution with copper electrodes (could be demonstrated whilst watching a video on refining copper).

Task: Candidates review/ investigate how aluminium is mined, extracted and purified by electrolysis.

Demo: Demonstration of electrolysis of molten zinc chloride or lead bromide.

ores.

Copper sulfate solution 0.5 mol dm-3, copper electrodes, power pack 100cm3 beaker, wires and light bulb.

Crucible, carbon electrodes, power supply, connecting wires, lamp, Bunsen burner and fume cupboard.

You can find a variety of resources including video clips on the RSC website at www.rsc.org/education/teachers/resources/alchemy/index/htm

RSC Alchemy a has section on aluminium at www.rsc.org/Education/Teachers/Resources/Alchemy/index2.htm

h Copper can be obtained from solutions of copper

Know that:

metals can be obtained

1 Activity: Displacement reactions using copper sulfate solution and a range of metals eg. Mg, Fe, Al, Zn.

VLE/Interactive software, eg chemical reactions.

Be able to evaluate the merits of a method of


http://www.rsc.org/Education/Teachers/Resources/Alchemy/index2.htm




http://www.rsc.org/education/teachers/resources/alchemy/index/htm




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i

salts by electrolysis or by displacement using scrap iron.

Aluminium and titanium cannot be extracted from their oxides by reduction with carbon. Current methods ofextraction are expensive because: there are many

stages in the processes

large amounts of energy are needed.

from solutions by displacement reactions with a more reactive metal

electrolysis requires vast amounts of electrical energy and therefore is expensive.

the more stages in a process the more expensive it becomes.

How Science Works: Produce a table of results. Discussion of variation in results.

Reactivity series could be established here and links to Data sheet and metal extraction made.

Homework/Homework: Candidates report experiment and from results establish their own reactivity series.

View the displacement reactions PowerPoint presentation at www.worldofteaching.com/powerpoints/chemistry/metals%20and%20acids.ppt

extraction in terms of cost and environmental impact .

g New ways of extracting copper from low-grade ores are being researched to limit the environmental impact of traditional mining. Copper can be extracted by phytomining, or by bioleaching.

Know andunderstand that:

phytomining uses plants to absorb metal compounds and that the plants are burned to produce ash that contains the metal compounds

bioleaching uses bacteria to produce leachate

1 Task: Candidates research the topics of phytomining and bioleaching, and produce notes on main features of the processes.

Or

Activity: With planning candidates could grow cabbage plants or other types of brassica plants to extract metal from contaminated soil, and

Further background information can be found at www.copper.org

See Exampro Extra Online Practical Guide.

Be able to work out what is happening when given an unfamiliar method of extraction of an ore or a metal.

Follow the metal through the diagram to see where it must be


http://www.copper.org/

http://www.worldofteaching.com/powerpoints/chemistry/metals%20and%20acids.ppt




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solutions that contain metal compounds.

process to obtain the metal. going in each step. Make notes on the diagram to help them.

j We should recycle metals because extracting them uses limited resources and is expensive in terms of energy and effects on the environment.

Evaluate benefits of recycling metals in terms of economic and environmental benefits.

1 Task: Working in pairs/groups, candidates research/find out the benefits of recycling metals such as iron, copper, aluminium, and produce a mini-project on it.

Or

Give groups of candidates a metal, and some questions. Candidates prepare an A4 sheet, poster or word document to email to rest of class about their answers.

Questions could be:

How is your metal extracted, and why is this method used?

What pollutants are produced in its extraction?

How much of the metal is re-cycled?

How is it recycled? Explain why recycling the metal is

Use RSC Alchemy disc for individual metals, or internet sites. More information can be found on the RSC Alchemy website at www.rsc.org/Education/Teachers/Resources/Alchemy/index2.htm

Access to internet, paper, poster paper, glue scissors and magazines.






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both good for the environment, economically sound (saves money), and saves on limited reserves of ores.

Candidates present five minute briefing on their metal.

This and the next lesson could become a single larger project into iron, steel, alloys and recycling metals to be environmentally friendly and economically successful.

C1.3.2 Alloys

a

b

Iron from the blast furnace contains about 96% iron. The impurities make it brittle and so it has limited uses.

Most iron is converted into steels. Steels are alloys since they are mixtures of iron with carbon. Some steels contain other metals. Alloys can be

Know the difference between iron from the blast furnace and steel in terms of less carbon in steel than iron from the blast furnace.

Know that the many types of steel are really alloys.

1 Task: Candidates complete a project on iron, steel and alloys to explain the differences.

Research: Research the meaning of ‘carat’ in relation to gold, and the reasons for the different proportions of gold in each type of gold.

Homework: Past paper question on properties of metals and their uses,

More information on Iron Section, can be found on the RSC Alchemy website at www.rsc.org/Education/Teachers/Resources/Alchemy/index2.htm

Note: there is no need for candidates to remember different combinations of alloys. Be able to interpret information provided.






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c

designed to have properties for specific uses. Low-carbon steels are easily shaped, high-carbon steels are hard, and stainless steels are resistant to corrosion.

Most metals in everyday use are alloys. Pure copper, gold, iron and aluminium are too soft for many uses and so are mixed with small amounts of similar metals to make them harder for everyday use.

Know that alloys have improved properties as a result of the combination of metal atoms.

from past CHY1 papers, eg Jan 07 CHY1F Q3, Jan 08 CHY1F Q6

C1.3.3 Properties and uses of metals

a The elements in the central block of the periodic table are known as transition metals. Like other metals they are good conductors of heat and

Know that the central block of the Periodic table are known as the Transition metals.Many commonly used metals are in this block.

Know and understand that

1 Task: Candidates view metal properties circus, this is KS3 revision. Candidates to make brief notes on properties of metals.

Activity: Draw attention to copper, aluminium and titanium as transition

Circus of metals to show their properties, eg bendable, and conductivity of heat and electricity.Metal samples such as iron (thin long nails or wire), copper foil, aluminium foil,

Concentrate on matching property to use of metals.

Note: Remember that some properties mean



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b

c

electricity and can be bent or hammered into shape. They are useful as structural materials and for making things that must allow heat or electricity to pass through them easily.

Copper has properties that make it useful for electrical wiring and plumbing.

Low density and resistance to corrosion make aluminium and titanium useful metals.

copper:

is a good conductor of electricity and heat

can be bent but is hard enough to be used to make pipes or tanks

does not react with water.

metals and their place on the periodic table as Transition metals. Candidates mark transition metals on their periodic table.

Discuss: Teacher-led discussion on properties and uses of copper, aluminium and titanium.

Task: Candidates make notes on properties and uses of these metals.

Homework: Exam question on using metals as structural materials, eg June 09 CHY1H Q6b

lead foil, and any others available, beakers and access to hot water, conductivity testing kit (power pack, wires, and bulb).

candidates shouldn’t use it for the application, eg sodium is not suitable for applications involving water.

C1.4 Crude Oil and Fuels Crude oil is derived from an ancient biomass found in rocks. Many useful materials can be produced from crude oil. Crude oil can be fractionally distilled. Some of the fractions can be used as fuels. Biofuels are produced from plant material. There are advantages and disadvantages to their use as fuels. Fuels can come from renewable or non-renewable resources.

C1.4.1 Crude oil

a Crude oil is a mixture of a very large number of compounds.

Know what a mixture is in terms of elements and compounds.

1/ 2 Recap what a mixture is, and explain that crude oil is a mixture.

Fake crude oil (CLEAPPS/Hazcard recipe), boiling tube with side arm, bung for boiling tube with 0 -

Note: Candidates are not expected to know the names of specific alkanes



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b

c

A mixture consists of two or more elements or compounds not chemically combined together. The chemical properties of each substance in the mixture are unchanged. It is possible to separate the substances in a mixture by physical methods including distillation.

Most of the compounds in crude oil consist of molecules made up of hydrogen and carbon atoms only (hydrocarbons). Most of these are saturated hydrocarbons called alkanes, which have the general formula CnH2n+2 .

Describe fractional distillation as based on each compound having a different boiling point.

Know that each compound vaporises and condenses at different temperatures, and so they are separated.

Describe the relationship between molecule size and boiling point, viscosity, ease of ignition, and flammability.

Recognise alkanes from theirformulae in any of the forms:C2H6

Describe what the structural formula shows.

Know the general formula for alkanes.

Demo: Experiment of distillation of crude oil (CLEAPPS recipe), followed by analysis and burning of obtained fractions.

Task: Candidates make diagram of experiment and chart the results from the demonstration:

fraction colour viscosity ease of ignition

amount of smoke

Discuss: Discuss how these properties affect how we use hydrocarbons as fuels, diesel in winter, amount of soot etc. Candidates make notes.

Discuss: Differences between the demo and fractional distillation as continuous process. Use video.

Name each formula and draw methane, ethane and propane as examples of alkanes in both forms. Show as models.

Elicit general formula for alkanes.

Discuss: the use of a line as

360OC thermometer, side arm, four test tubes, 250cm3 beaker, four watch glasses, heat mat, matches and spills and fume cupboard.

Molymods or similar.

Information and videos of fractional distillation can be found on BBC GCSE Bitesize at www.bbc.co.uk/schools/gcsebitesize

VLE/Interactive software eg ‘organic chemistry ‘and ‘useful organic’.

RSC Alchemy disc has a section on Oil Refining. This

other than methane, ethane and propane.





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representing a single covalent bond.

Task: Candidates draw molecular diagrams adding in notes to the diagrams of methane, ethane, and propane as alkanes.

can also be found at www.rsc.org/Education/Teachers/Resources/Alchemy/index2.htm

C1.4.2 Hydrocarbons

b

c

The many hydrocarbons in crude oil may be separated into fractions, each of which contains molecules with a similar number of carbon atoms, by evaporating the oil and allowing it to condense at a number of different temperatures. This process is fractional distillation.

Some properties of hydrocarbons depend on the size of their molecules. These properties influence how hydrocarbons are

Homework: Give formulae of five more hydrocarbons and ask candidates to draw the long chain molecule (ignore isomers).

Know how fractional distillation works as this is generally poorly understood.






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used as fuels.

C1.4.3 Hydrocarbon fuels

a

c

d

e

Most fuels, including coal, contain carbon and/or hydrogen and may also contain some sulfur.

Sulfur dioxide causes acid rain, carbon dioxide causes global warming, and solid particles cause global dimming.

Sulfur can be removed from fuels before they are burned, for example in vehicles. Sulfur dioxide can be removed from the waste gases after combustion, for example in power stations.

Biofuels, including

Know that burning fuels releases carbon dioxide, water (vapour), carbon monoxide, sulfur dioxide and oxides of nitrogen into the atmosphere. Solid particles (particulates) may also be released.

Know that these cause global warming acid rain and global dimming.

Know how harmful emissions are reduced.

1 Demo: Burning a candle, and passing exhaust gases through anhydrous copper sulfate/cooling U tube and cobalt chloride paper, then limewater.

How Science Works: Draw attention to need for control experiment to compare the results. Candidates label diagram and make results chart.

Note: Soot formation by incomplete combustion.

Discuss: candle wax is purified hydrocarbon, and many fuels contain sulfur compounds which cause acid rain. Carbon dioxide causes global warming and soot particles cause dimming.

Equipment as in diagram.See AQA website Practical Guide

VLE/Interactive software eg, ‘useful air’ and ‘Earth and atmosphere’.

Know that products of combustion depend on the elements present in the fuel (check the formula) and how much oxygen is present. Carbon monoxide is made if there is not enough oxygen present for complete combustion, but really serious shortage of oxygen makes soot (carbon).

Note: Detailed knowledge of the processes is not required.

Be able to explain why removing


candle here


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biodiesel and ethanol, are produced from plant material. There are economic, ethical and environmental issues surrounding their use.

Task: Candidates make notes on experiment.

Discuss: Class discussion on reducing harmful effects of sulfur in fuels.

Research: the methods used, including removing the sulfur from the fuel before burning, eg low-sulfur fuels, or for removal of sulfur dioxide from the waste gases after combustion. Candidates make notes.

Homework: Past paper question on the uses of fuels.

Access to internet.

sulfur from fuels is good for the environment.

Describe the use of ethanol and hydrogen as alternative fuels.

Describe advantages and disadvantages of each fuel.

1 Task: Arrange candidates in groups produce a plus (advantages), minus (disadvantages), and interesting poster/sheet evaluating both ethanol, and hydrogen as possible fuels for transport systems.

Discuss: Class discussion/presentation on findings.

BMW have a video on hydrogen cars which can be found at http://vodpod.com/watch/4039285-test-drive-bmw-hydrogen-car

Exampro Extra Online chemistry activity – alternative fuels video clip projects.

Note: Candidates do not need to remember the methods of production.

Be able to describe why one method is better than another.


http://vodpod.com/watch/4039285-test-drive-bmw-hydrogen-car




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More information on ethanol as fuel can be found on the 60 Minutes website at www.cbsnews.com by searching for ‘The Ethanol Solution’.

b The combustion of hydrocarbon fuels releases energy. During combustion the carbon and hydrogen in the fuels are oxidised.

Know how to measure simply the amount of energy produced by a burning fuel.

Know about different types of error, and how to deal with them.

Understand how secondary sources can help confirm a hypothesis/ theory.

1 Task: Candidates investigate the energy produced when a fuel is burnt, eg an alcohol, or a food such as Weetabix etc.

How Science Works: Outline task and get class to come up with equipment needed and how it is to be used.

Task: Candidates should report their investigation.

How Science Works: Draw out ideas of reproducibility of results and using other people’s data/secondary sources to confirm findings. Also good point to mention types of errors eg zero error, systematic error, random errors and how to deal with them.

Homework: Complete the write-up, and/or make notes on definitions of

Boiling tube/beaker.

Tripod, gauze, fuel burner eg alcohol burner, micro-burner, candle, mounted needle to hold Weetabix bottle top, balance and measuring cylinders.

Be able to determine what areas of this experiment can be improved.


http://www.cbsnews.com/


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errors and how to deal with them.



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C1.5 Other useful substances from crude oil. Fractions from the distillation of crude oil can be cracked to make smaller molecules including unsaturated hydrocarbons such as ethene. Unsaturated hydrocarbons can be used to make polymers and ethene can be used to make ethanol. Ethanol can also be made by fermentation.

C1.5.1 Obtaining useful substances from crude oil

a

b

Hydrocarbons can be broken down (cracked) to produce smaller, more useful molecules. This process involves heating the hydrocarbons to vaporise them.

The vapours are either passed over a hot catalyst or mixed with steam and heated to a very high temperature so that thermal decomposition reactions then occur.

The products of cracking include alkanes and

Recall that heating large alkanes with a catalyst or steam and hot temperature decomposes to make the hydrocarbon smaller molecules.

Know that some of these smaller molecules are called alkenes.

1 Task: List five products from crude oil, and ask how we get enough of each of them. It is interesting to tell candidates that 100 years ago petrol was a waste product, but now we can’t get enough of it!

Demo: Demonstrate cracking or use video to show process of cracking. Candidates make notes.

Explain: That cracking makes larger molecules into smaller, more useful ones, including a group of compounds called alkenes.

Task: Candidates draw diagrams to explain cracking.

VLE/Interactive software eg organic chemistry.

You can find a variety of resources including video clips on the RSC website at www.rsc.org/Education/Teachers/Resources/Alchemy/index.htm

See Exampro Extra Online Practical Guide: Cracking liquid paraffin.

See Exampro Extra Online Chemistry Activity: Crude oil word puzzles.

Be able to recognise ‘n’ alkene by the double bond in its structure, or that the name ends in –‘ene’.






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unsaturated hydrocarbons called alkenes.

b

cd

e

Alkeneshave the general formula CnH2n .

Alkenes react with bromine water, turning it from orange to colourless.

Some of the products of cracking are useful as fuels.

Recognise alkenes from theirformulae in any of the forms:C3H6

Know that ‘=’ represents a double bond in the structure.

Know that cracking produces more useful molecules including alkenes and fuels.

Know that the presence of double bonds in a molecule can be tested for by the decolorisation of bromine water.

1 Discuss: Introduce idea of double bond using structural formula of ethane and propene.

Activity: Class practical testing for double bonds using bromine water. Candidates should test a range of named alkenes and alkanes. Candidates make notes.

Explain: Show with models how breaking large molecules produces not only alkenes, but also more fuels like petrol (octane) and diesel (dodecanes).

Task: Candidates draw diagrams to explain the above.

Homework: Candidates predict reactions of a variety of molecules displaying single and double bonds with bromine water.

VLE/Interactive software, eg organic chemistry.

Bromine water, test tubes, test tube racks, liquid alkanes, eg pentane, hexane, liquid alkenes, eg hexene, cyclohexene.

Molymods

Remember that ‘=’ means a double covalent bond, and that ‘-‘ means a single covalent bond. A double bond means that the compound is unsaturated. A single bond means that the compound is saturated.



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C1.5.2 Polymers

a Alkenes can be used to make polymers such aspoly(ethene) and poly(propene). In these reactions,many small molecules (monomers) join together toform very large molecules (polymers).

Represent polymerisation of ethene like this

1 Demo: Making Perspex.

Use molecular models to demonstrate how polymers form.

Class make own polymer chain by:

each candidate making a monomer either with model or drawn onto front of paper chain piece.

two candidates joining their monomer together and drawing on back structure at the joining.

groups joining together to make long chain with monomer structure on front of each piece of paper and polymer structure on rear of chain.

Candidates draw diagrams to explain ethene polymerisation.

Homework: Candidates to draw diagrams showing propene polymerisation.

Exampro Extra Online Practical Guide: see AQA help notes.

Molymods

Paper chain pieces (use waste paper) and marker pens.


RSC Alchemy disc has section on poly(ethene). Further information can be found at www.rsc.org/Education/Teachers/Resources/Alchemy/index2.htm

Note: Candidates only need to learn the basic polymerisation of ethene, as the propene simply changes one H atom for a CH3 group.






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b

c

d

Polymers have many useful applications and new uses are being developed, for example: new packaging materials, waterproof coatings for fabrics, dental polymers, wound dressings, hydrogels, smart materials (including shape memory polymers)

Many polymers are not biodegradable: so they are not broken down by microbes and this can lead to problems with waste disposal.

Plastic bags are being made from polymers and cornstarch so that they break down more easily. Biodegradable plastics made from cornstarch have been developed.

Know that we use a wide range of polymers developed for specific purposes.

Identify from properties relevant uses for a polymer.

Realise that polymers are often hard to dispose of, and that biodegradable ones offer some solutions to these problems.

1/2 Activity: Choose from

making a polymer from cornstarch testing a polymer’s strength eg

plastic carrier bag testing strength to breaking point (not a Hookes’ Law investigation)

testing waterproofing of different polymer fabrics

investigating the amount of water absorbed by hydrogels.

How Science Works: Candidates plan and report their investigation.

Homework: Recycling plastics – give two advantages and two disadvantages of recycling plastics.

See Exampro Extra Online Practical Guide.



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Be aware that crude oil is used to produce fuels and chemicals, and that it is a limited resource.

Evaluate information about the ways in which crude oil and its products are used.

1 Task: Working in pairs, candidates answer this question – should we burn oil as a fuel, or should we make it into polymers and other chemicals?

They give two advantages and two disadvantages of burning products of crude oil rather than using them to make polymers and other chemicals. They link with another pair to build up bigger lists, and then larger groups link to eventually produce a single class list of advantages and disadvantages.

Candidates make notes. Allow pairs to decide their answer to the question and hold a vote.

Candidates complete a worksheet on evaluating the uses of crude oil and how crude oil products are used.



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1.5.3 Ethanol

a

b

Ethanol can be produced by reacting ethene with steam in the presence of a catalyst.

No further details of these processes are required.

Ethanol can also be produced by fermentation with yeast, using renewable resources.

Know that ethanol can be made from ethane and steam, or by yeast:

sugar carbon + ethanol dioxide

Compare the environmental impact of producing ethanol from renewable and non-renewable sources.

1 Activity: Making ethanol with yeast. (you could start the culture in the previous lesson and identify the ethanol by either distillation or by aroma). Candidates make notes.

Discuss: Evaluate the advantages and disadvantages of making ethanol from renewable and non-renewable sources.

Homework: Past paper questions/ worksheet on advantages and disadvantages of making ethanol from renewable and non-renewable sources.

Sugar, yeast, limewater, 250 cm3 conical flask and bung with delivery tube.

Distillation apparatus




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C1.6 Plant oils and their uses Many plants produce useful oils that can be converted into consumer products including processed foods. Emulsions can be made and have a number of uses. Vegetable oils can be hardened to make margarine. Biodiesel fuel can be produced from vegetable oils.C1.6.1 Vegetable oils

a

b

c

Some fruits, seeds and nuts are rich in oils that can be extracted. The plant material is crushed and the oil removed by pressing or in some cases by distillation.Water and other impurities are removed.

Vegetable oils are important foods and fuels as they provide a lot of energy. They also provide us with nutrients.

Vegetable oils have higher boiling points than water and so can be used to cook foods at higher temperatures than by boiling. This

Know two ways in which vegetable oils are obtained.

Know that cooking in vegetable oils allows food to be heated to higher temperatures causing different chemical changes to those brought about by boiling in water.

1 Demo: Extraction of lavender oil or orange/lemon oil by steam distillation.

Task: Candidates draw diagrams to explain the above.

Discuss: Crushing of olives/nuts to provide plant oils as well. Research how olive oil is made. Candidates make notes.

Biofuels, waste vegetable fat, diesel and ethanol can all be used as fuels.

Discuss the positives, negatives and risks in using plant material to produce and use as fuels, eg renewable, but there is the possibility of crop failure. Do the gases produced on combustion add to global warming, and other pollutants? How can these gases be stored and used?

Role of oils (and fats) in cooking.

Exampro Extra Online Practical Guide see help notes.

Access to internet or other resources.

Please refer to the BBC report on biofuels which can be found on the BBC website at www.bbc.co.uk by searching for ‘Quick guide: Biofuels’ .


http://www.bbc.co.uk/


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produces quicker cooking and different flavours but increases the energy that the food produces when it is eaten.

Candidates could discuss boiled potatoes and chips; compare flavour, texture, cooking time and smell. Candidates make notes.

C1.6.2 Emulsions

a

b

Oils do not dissolve in water. They can be used to produce emulsions. Emulsions are thicker than oil or water and have many uses that depend on their special properties. They provide better texture, coating ability and appearance, for example in salad dressings, ice creams, cosmetics and paints.

HT only Emulsifiers have hydrophilic and hydrophobicproperties.

Know how emulsifying agents can help oil and water mixtures to remain mixed.

Give two uses of emulsions.

Identify anomalous results, and calculate a mean from them

Plot a graph or bar chart appropriate to the data collected.

Draw a simple representation of a molecule with hydrophobic and hydrophilic ends.

1 Activity: Making an emulsion. Oil and water using an emulsifying agent such as egg, mustard, lecithin. Investigate using different emulsifiers.

How Science Works: Identify risks in the practical, and how to control them. Identifying variables to control.

Task: Candidates investigate time taken for the emulsion to separate out. Candidates report their experiment.

How Science Works: Good time to explain need for repeatability, precision, and reliability of results. Also an opportunity to deal with means. As the results can be categoric or continuous it is also sensible to discuss graph plotting.

Vegetable oil, emulsifying agent, 10 cm3 measuring cylinders, boiling tubes with bungs and stopwatches.Exampro Extra Online Practical Guide: Using different emulsifiers to make emulsions

Always remember to give the calculated mean value to the same number of decimal places as the original results.



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Discuss: Why we need emulsifiers in foods and the risks they can pose.

HT only Show simple diagram of water-hating (hydrophobic) and water-liking (hydrophilic) ends to a molecule to explain the role of the emulsifying agent.

Homework: Candidates draw diagram/make notes to explain.

C1.6.3 Saturated and unsaturated oils

a

b

Vegetable oils that are unsaturated contain double carbon–carbon bonds. These can be detected by reacting with bromine water.

HT only Vegetable oils that are unsaturated can be hardened by reacting them with hydrogen in the presence of a nickel catalyst at about

Know how to determine the relative amounts of saturation in an oil/fat by using bromine water.

1 Activity: Flora rather than butter! (consider all possibilities). Produce list of reasons why Flora is ‘healthier’ than butter.

Activity: Test fats and oils, eg butter/lard, dripping against margarines or oils to determine amount of saturation using bromine water test. Candidates report their experiment.

How Science Works: Another opportunity to visit ideas of means, precision and accuracy. Did we control

Bromine water, test tubes, test tube racks, ethanol, hot water, 250 cm3 beakers, selection of fats and oils 10 cm3 measuring cylinder, pipette and balance .

Remember, the more bromine water is decolourised the more double bonds there are present in a sample of oil (for the same volume).



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60°C.Hydrogen adds to the carbon–carbon double bonds. The hydrogenated oils have higher melting points so they are solids at room temperature, making them useful as spreads and in cakes and pastries.

all the variables? If not are our results valid?

Discuss: Health benefits of vegetable oils rather than animal fats in the diet.

HT only Discuss: how we can harden vegetable oils to make them solids at room temperature.

Homework: Candidates make magazine advert on health benefits of vegetable oils in the diet.



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C1.7 Changes in the Earth and its atmosphere The Earth and its atmosphere provide everything we need. The Earth has a layered structure. The surface of the Earth and its atmosphere have changed since the Earth was formed and are still changing. The atmosphere has been much the same for the last 200 million years and provides the conditions needed for life on Earth. Recently human activities have resulted in further changes in the atmosphere. There is more than one theory about how life was formed.C1.7.1 The Earth’s crust

a

b

The Earth consists of a core, mantle and crust, and is surrounded by the atmosphere.

The Earth’s crust and the upper part of the mantle are cracked into a number of large pieces (tectonic plates).

Know the three parts of the Earth, and the atmosphere.

Know that all our resources come for the crust, the seas, or the air.

Know key features of Wegener’s theory, and evidence to support it.

Explain why no one believed the theory at first.

1 Task: Name parts of the earth and relative sizes.Candidates draw diagrams to explain

Discuss: existence of plates, including brief mentions of volcanoes and earthquakes.

Use a resource to investigate Wegener’s theory of crustal movement.Candidates make notes.

Leave lesson hanging with the fact that no one knew how the Earth’s plates could move, so the theory could not be accepted.

VLE/Interactive software, eg Earth and atmosphere.

Exampro Extra Online Chemistry Activity: Earth structure determination.

View the Earth structure PowerPoint presentation at www.bgu.ac.il/geol/classes/tectonics/Front/tectonics_lec_01.ppt

Note: Candidates do not need to remember the plates, their names or the direction of movement.

Know that volcanoes and earthquakes are found at the edges of the plates.

c Convection currents Know that convection currents 1 Discuss: How Wegener’s theory was Instant custard (or, if making Remember the


http://www.bgu.ac.il/geol/classes/tectonics/Front/tectonics_lec_01.ppt




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d

within the Earth’s mantle driven by heat released by natural radioactive processes cause the plates to move at relative speeds of a few centimetres per year.

The movements can be sudden and disastrous.Earthquakes and/or volcanic eruptions occur at the boundaries between tectonic plates.

driven by the heat from radioactive processes cause the movement of the plates.

Explain what earthquakes are and why we cannot predict them

Explain what volcanoes are and why we cannot predict their eruptions.

accepted. What extra evidence was needed.

How Science Works: Candidates think up what evidence they would want to know before they could accept the theory.

Demo: experiment using custard or tomato soup and cardboard cutouts of continents to demonstrate how the mantle allows plates to move slowly across the surface of the Earth.

Discuss: Source of heat. Candidates draw diagrams to explain.

Explain: how earthquakes occur and why we cannot predict them accurately.

Explain: why volcanoes erupt and why we cannot predict eruptions accurately. Candidates make notes.

it, halve water amount so it is thick), large pyrex glass dish/ beaker, cut outs in shape of South America and Africa, Bunsen burner, tripod etc.


Exampro Extra Online Chemistry Activity: Natural disasters

View the Earth structure PowerPoint presentation at www.bgu.ac.il/geol/classes/tectonics/Front/tectonics_lec_01.ppt

mantle is mainly solid so movement is very slow, unlike hot custard.

Note: Knowledge of the changes that occur at plate boundaries is limited to earthquakes and volcanic eruptions. Knowledge of the mechanism of these changes is not required.

C1.7.2 The Earth’s atmosphere

a For 200 million years, the proportions of different gases in the

Describe the atmosphere today.

1 Demo: on the gases present in the air. Best one is the classic two syringes one using copper, followed by burning







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l

atmosphere have been much the same as they are today:

about four-fifths (80%) nitrogen

about one-fifth (20%) oxygen

small proportions of various other gases

including carbon dioxide, water vapour and noble gases.

HT only Air is a mixture of gases with different boiling points and can be fractionally distilled to provide a source of raw materials used in a variety of industrial processes.

HT only Describe how we obtain pure gases from the mixture we call air.

magnesium in the nitrogen and making ammonia.

Task: Candidates draw diagrams and chart of gases in air today to explain. They may want the charts to have a blank column for the early atmosphere to fill in next lesson.

HT onlyView and make notes on gases from air video.

RSC Alchemy disc has section on gases from the air. Further information can be found at www.rsc.org/Education/Teachers/Resources/Alchemy/index.htm

A video on Joseph Priestley and the discovery of gases can be found on the BBC website at www.bbc.co.uk/learningzone/clips by searching for clip’2078’

b During the first billion years of the Earth’s

Know that: our atmosphere

1 Task: Complete the chart from last lesson by adding in the early









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c

d

existence there was intense volcanic activity. This activity released the gases that formed the early atmosphere and water vapour that condensed to form the oceans.

There are several theories about how the atmosphere was formed.

One theory suggests that during this period the Earth’s atmosphere was mainly carbon dioxide and there would have been little or no oxygen gas (like the atmospheres of Mars and Venus today). There may also have been water vapour and small proportions of methane and ammonia.

originated from volcanic gases

water vapour condenses to make the seas

simple organisms evolved producing oxygen by photosynthesis

plants and animals evolved later

there is evidence for amounts of oxygen in the air at different times.

atmosphere and discussing how it mainly came from the volcanoes. Explain ocean formation and how the oceans became ‘salty’.

Discuss: evidence for atmosphere evolution.

Task: Candidates make timeline for key dates in changes of atmosphere, eg start of life on land, start of animal life, other evidence for amount of oxygen in air.

Discuss: conditions necessary for life to exist.

Explain: the need for oxygen, provided by photosynthesis. Candidates make notes.

View the early atmosphere PowerPoint presentation at http://sallyholl.com/science/ppt/evolution_of_atmosphere.ppt


http://sallyholl.com/science/ppt/evolution_of_atmosphere.ppt




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f

d

e

Plants and algae produced the oxygen that is now in the atmosphere.

There are many theories as to how life was formed billions of years ago.

HT only One theory involves the interaction between hydrocarbons, ammonia and lightning.

HT only Refer to Miller-Urey and the primordial soup experiment. Candidates make notes.

Homework: Produce newspaper front page report for the headline, ‘Oxygen hits the atmosphere’ Dateline 3.6 billion years ago.

See Giant Leaps by The Sun ISBN 978 0752226248 for ‘primordial soup’.

Note: The Miller-Urey experiment is not the only theory of life development. As with all theories there are other competing ones.

g

h

Most of the carbon from the carbon dioxide in the air gradually became locked up in sedimentary rocks as carbonates and fossil fuels.

The oceans also act as a reservoir for carbon dioxide but

Describe how carbon cycles round the earth and atmosphere.

Describe how human activity has affected the proportions in each part of the cycle.

1 Activity: Testing animal shells for carbonates.

Discuss: Discussion and construction of a chemical carbon cycle showing carbon present as:

CO2 in the air CO2 in the sea carbonates as shells carbonates as sedimentary rocks carbon in living things

Exampro Extra Online Practical Guide help notes.

VLE/Interactive software eg Earth and atmosphere.

Understand that most scientists believe that the rate that we are now producing CO2

is too fast for the planet ‘to take it up’.



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i

increased amount of carbon dioxide absorbed by the oceans has an impact on the marine environment.

Nowadays the release of carbon dioxide by burning fossil fuels increases the level of carbon dioxide in the atmosphere.

fossil fuels

Overlay how human impact has changed these levels, eg in the air it increases by burning fossil fuels, use of fossil fuels and carbonate rocks as ores and building materials, more CO2 dissolving in water causing increased acidity of oceans.

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