Unit 2 – Chemistry
This 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. The new Chemistry Activities and Practical Guides are held in Exampro Extra Online, which is a free resource for AQA teachers.
*The suggested timings relate to the learning outcomes rather than to the activities.
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.
Reference / Summary of the Specification Content / Learning OutcomesWhat 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
b
c
d
e
f
g / All substances are made of atoms.
Atoms are represented by symbols.
Atoms have a small central nucleus, of protons and neutrons, surrounded by electrons
two of these particles are charged
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. / Know that substances are made of atoms. State that 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. / 1 / Activity: Use the Periodic table to elicit answers about:
· 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 diagrams or chart in books.
Homework: Candidates draw structures of several named atoms using the periodic table. / Periodic table/ data sheet for chemistry
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 / Be able to use symbols 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.
h / Electrons occupy particular energy levels. Each electron in an atom is at a particular energy level (in a particular shell). The electrons in an atom occupy the lowest available energy levels (innermost available shells). / 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 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).
They do not have full outer shells, except for He and Ne. From Ne onwards they have 8 electrons in their outer shell. / Electron shell diagram sheet with elements placed in same position as Periodic table, elements 1 – 20.
VLE/Interactive software eg periodic table slides.
View the electron shell PowerPoint presentation at http://education.jlab.org/jsat/powerpoint/chembond.ppt
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 helium, which has two. / Demo: Li, Na and K with water. Show H2 gas produced and alkali solution as well.
How Science Works: Make observation.
Task: Candidates describe tests and write word equations for the reactions.
How Science Works: Making a prediction. Ask candidates what they think reaction of Cs would be, show video clip of reaction with water.
Demo: Burning Li, Na and K in air to react with oxygen. / Large glass trough
universal 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 of
similarities between the elements within a group.
C1.1.3 Chemical reactions
b / Chemical reactions can be represented by word
equations / Write word equations to represent reactions. / 1 / Task: Candidates write one word equation to show general reaction.
Note: 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’
Useful video clips can be found on the Royal Society of Chemsitry (RSC) website at www.rsc.org/education/teachers/resources
Multi-media science school for Caesium 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
Balance a given symbol equation. / 1 / Review idea of word equation and introduce symbol equations.
Explain: Show need for balancing the equation linked to idea of conservation of mass.
Task: Candidates to balance several equations themselves. / VLE/Interactive software eg chemical reactions.
a / When elements react, their atoms join with other atoms to form compounds. This involves giving, taking
or 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’.
RSC video clips c an be found at www.rsc.org/education/teachers/resources
Gas jar chlorine, deflagrating spoon, small piece of sodium, Bunsen burner, and fume cupboard.
VLE/Interactive software, eg Bonding.
View the bonding PowerPoint presentation at http://education.jlab.org/jsat/powerpoint/chembond.ppt / Note: Further details of the types of
bonding are not required.
Know that
metals lose electrons to form positive ions, whereas non-metals gain electrons to form negative ions.
Know that such transfers are limited to single electrons.
c / No atoms are lost or made during a chemical reaction
so 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).
Understand 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. 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 reactant. / Balances, boiling tubes, 25cm3 measuring cylinders, lead nitrate solution 1mol dm-3 potassium iodide 1 mol dm-3 / Be able to calculate
the mass of a reactant or
product from information
about the masses of the
other reactants and products in the reaction.
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: /
C1.2 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
e / Limestone, mainly composed of the compound
calcium 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.
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. / 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:
· 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. / 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 given them. / 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
Limestone/marble chips, matches and spills, watch glass, filter funnel, filter paper, 100 cm3 conical flask, evaporating basin, boiling tube and clean straw. / Note: Knowledge of the common
names quicklime and slaked
lime is not required.
Be familiar
with using limewater to test
for carbon dioxide gas.
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.