This document compares the specification learning outcomes from the legacy GCSE Twenty century Chemistry qualification to the new GCSE (9-1) in Twenty first century Chemistry. It shows where the statements in the old specification are covered in the new spec, indicates where they are no longer assessed and highlights where new content has been added. Spec Ref Original spec statement (21C current spec) Spec Ref Spec statement equivalent (reformed 21C spec) tick if no longer covered C1.1.1 recall that the atmosphere (air) that surrounds the Earth is made up mainly of nitrogen, oxygen and argon, plus small amounts of water vapour, carbon dioxide and other gases C1.1.4 use data to predict states of substances under given conditions  C1.1.2 recall that air is a mixture of different consisting of small molecules with large spaces between them N/A  C1.1.3 recall that the relative proportions of the main gases in the atmosphere are approximately 78% nitrogen, 21% oxygen and 1% argon C1.1.4 use data to predict states of substances under given conditions  C1.1.4 understand that gases or particulates may be released into the atmosphere by human activity or by natural processes (e.g. volcanoes), and that these can affect air quality C1.1.7 describe the major sources of carbon monoxide and particulates (incomplete combustion), sulfur dioxide (combustion of sulfur impurities in fuels), oxides of nitrogen (oxidation of nitrogen at high temperatures and further oxidation in the air)  C1.1.5 understand how the Earth’s early atmosphere was probably formed by volcanic activity and consisted mainly of carbon dioxide and water vapour C1.1.5 interpret evidence for how it is thought the atmosphere was originally formed  C1.1.6 understand that water vapour condensed to form the oceans when the Earth cooled C1.1.5 interpret evidence for how it is thought the atmosphere was originally formed 
C1.2.4 understand that a substance chemically combining with oxygen is an example of oxidation, that loss of oxygen is an example of reduction, and that combustion reactions therefore involve oxidation C4.5.2 explain reduction and oxidation in terms of loss or gain of oxygen, identifying which species are oxidised and which are reduced  C1.2.5 understand that fuels burn more rapidly in pure oxygen than in air N/A  C1.2.6 recall that oxygen can be obtained from the atmosphere and can be used to support combustion (e.g. in oxy-fuel welding torches) NA  C1.2.7 understand that in a chemical reaction the properties of the reactants and products are different use the names and symbols of the first 20 elements, Groups 1, 7 and 0 and other common elements from a supplied Periodic Table to write formulae and balanced chemical equations where appropriate use the names and symbols of common elements and compounds and the principle of conservation of mass to write formulae and balanced chemical equations and ionic equations 
C1.2.8 understand that atoms are rearranged during a chemical reaction use the and symbols of the first 20 elements, Groups 1, 7 and 0 and other common elements from a supplied Periodic Table to write formulae and balanced chemical equations where appropriate use the names and symbols of common elements and compounds and the principle of conservation of mass to write formulae and balanced chemical equations and ionic equations  C1.2.9 interpret representations of the rearrangement of atoms during a chemical reaction use the names and symbols of the first 20 elements, Groups 1, 7 and 0 and other common elements from a supplied Periodic Table to write formulae and balanced chemical equations where appropriate use the names and symbols of common elements and compounds and the principle of conservation of mass to write formulae and balanced chemical equations and ionic equations 
C2.4.5 . understand that nanoparticles can be used to modify the properties of materials, and give examples including: a. the use of silver nanoparticles to give fibres antibacterial properties b. adding nanoparticles to plastics for sports equipment to make them stronger describe the surface area to volume relationship for different-sized particles and describe how this affects properties describe how the properties of nanoparticulate materials are related to their uses including properties which arise from their size, surface area and arrangement of atoms in tubes or rings  C2.4.6 understand that some nanoparticles may have harmful effects on health, and that there is concern that products with nanoparticles are being introduced before these effects have been fully investigated. C4.4.5 explain the possible risks associated with some nanoparticulate materials including: a) possible effects on health due to their size and surface area b) reasons that there is more data about uses of nanoparticles than about possible health effects c) the relative risks and benefits of using nanoparticles for different purposes  C3.1.1 understand that movements of tectonic plates mean that the parts of ancient continents that now make up Britain have moved over the surface of the Earth NA  C3.1.2 understand how geologists use magnetic in rocks to track the very slow movement of the continents over the surface of the Earth NA  C3.1.3 understand that the movements of continents means that different rocks in Britain formed in different climates NA  C3.1.4 understand how processes such as mountain building, erosion, sedimentation, dissolving and evaporation have led to the formation of valuable resources found in England including coal, limestone and salt NA 
C3.3.13 understand that there may be disadvantages of chlorinating drinking water, including possible health problems from traces of chemicals formed by reaction of chlorine with organic materials in the water C1.4.1 describe the principal methods for increasing the availability of potable water, in terms of the separation techniques used, including the ease of treating waste, ground and salt water including filtration and membrane filtration; aeration, use of bacteria; chlorination and distillation (for salt water)  C3.3.14 understand that an electric current can be used to bring about chemical change and make new chemicals through a process called electrolysis C3.3.1 describe electrolysis in terms of the ions present and reactions at the electrodes  C3.3.15 recall that chlorine is now obtained by the electrolysis of salt solution (brine) i Technical details and the ionic reactions are not required C3.3.7 describe competing reactions in the electrolysis of aqueous solutions of ionic compounds in terms of the different species present, including the formation of oxygen, chlorine and the discharge of metals or hydrogen linked to their relative reactivity  C3.3.16 recall examples of important uses by industry of the sodium hydroxide, chlorine and hydrogen produced by electrolysis of brine NA  C3.3.17 interpret data about the environmental impact of the large scale electrolysis of brine NA  C3.4.1 understand that there is a large number of industrial chemicals with many widespread uses, including consumer products, for which there is inadequate data to judge whether they are likely to present a risk to the environment and/or human health NA  C3.4.2 . understand that some toxic chemicals cause problems because they persist in the environment, can be carried over large distances, and may accumulate in food and human tissues NA 
C3.4.3 recall that PVC is a polymer that contains chlorine as well as carbon and hydrogen NA  C3.4.4 understand that the plasticizers used to modify the properties of PVC can leach out from the plastic into the surroundings where they may have harmful effects NA  C3.4.5 understand that a Life Cycle Assessment (LCA) involves consideration of the use of resources including water, the energy input or output, and the environmental impact, of each of these stages: a. making the material from natural raw materials b. making the product from the material c. using the product d. disposing of the product C4.5.4 describe the basic principles in carrying out a life-cycle assessment of a material or product including a) the use of water, energy and the environmental impact of each stage in a life cycle, including its manufacture, transport and disposal b) incineration, landfill and electricity generation schemes c) biodegradable and non-biodegradable materials  C3.4.6 when appropriate information from a Life Cycle Assessment (LCA), compare and evaluate the use of different materials for the same purpose. C4.5.5 interpret data from a assessment of a material or product  C4.1.1 understand that atoms of each element have different proton numbers C2.2.1 explain how the position of an element in the Periodic Table is related to the arrangement of electrons in its atoms and hence to its atomic number C4.1.2 understand that arranging the elements in order of their proton numbers gives repeating patterns in the properties of elements C2.2.1 explain how the position of an element in the Periodic Table is related to the arrangement of electrons in its atoms and hence to its atomic number  C4.1.3 understand that early attempts to find connections between the chemical properties of the elements and their relative atomic mass were dismissed by the scientific community NA 
C4.1.24 use qualitative and quantitative data to identify patterns and make predictions about the properties of the Group 7 elements (for example melting point, boiling point, formulae of compounds and relative reactivity) C2.2.7 predict possible reactions and probable reactivity of elements from their positions in the Periodic Table  C4.1.25 understand that the halogens become less reactive as the group is descended and give examples to show this C2.2.7 predict possible reactions and probable reactivity of elements from positions in the Periodic Table  C4.1.26 understand how a trend in reactivity for halogens can be shown by their displacement reactions and by their reactions with alkali metals and with iron C2.2.6 recall the simple properties of Group 7 elements including their states and colours at room temperature and pressure, their colours as gases, their reactions with Group 1 elements and their displacement reactions with other metal halides  C4.1.27 state and explain the safety precautions necessary when working with the halogens NA  C4.1.28 recall the formulae of: a. hydrogen, water and halogen (limited to chlorine, bromine and iodine) molecules b. the chlorides, bromides and iodides (halides) of Group 1 metals (limited to lithium, sodium and potassium) C2.4.1 use chemical symbols to write the formulae of elements and simple covalent and ionic compounds  C4.1.29 write word equations for reactions of alkali metals and halogens in this module and for other reactions when given appropriate information C2.4.3 use the names and symbols of the first 20 elements, Groups 1, 7 and 0 and other common elements from a supplied Periodic Table to write formulae and balanced chemical equations where appropriate  C4.1.30 interpret symbol equations, including the number of atoms of each element, the number of molecules of each element or covalent compound and the number of ‘formulas’ of ionic compounds, in reactants and products C3.2.3 use the and symbols of common elements and compounds and the principle of conservation of mass to write formulae and balanced chemical equations and ionic equations 
C5.2.15 interpret the results of tests for carbonate, chloride, bromide, iodide and sulfate ions given a data sheet of tests for negatively charged ions and appropriate results (using dilute acid, lime water, silver nitrate and barium chloride or barium nitrate as the reagents). C5.2.4 describe tests to identify aqueous cations and aqueous anions and identify species from test results including: PAG5 a) tests and expected results for metal ions in solution by precipitation reactions using dilute sodium hydroxide (calcium, copper, iron(II), iron(III), zinc) b) tests and expected results for carbonate ions (using dilute acid), chloride, bromide and iodide ions (using acidified dilute silver nitrate) and sulfate ions (using acidified dilute barium chloride or acidified barium nitrate)  C5.3.1 recall that the Earth’s lithosphere (the rigid outer layer of the Earth made up of the crust and the part of the mantle just below it) is made up of a mixture of minerals NA  C5.3.2 recall that diamond and graphite are minerals, both of which are composed of carbon atoms C4.3.6 explain the properties of diamond and graphite in terms of their structures and bonding, include melting point, hardness and (for graphite) conductivity and lubricating action  C5.3.3 explain the properties of diamond in terms of a giant structure of atoms held together by strong covalent bonding (for example, melting point, boiling point, hardness, solubility and electrical conductivity) C4.3.6 explain the properties of diamond and graphite in terms of their structures and bonding, include melting point, hardness and (for graphite) conductivity and lubricating action  C5.3.4 understand how the giant structure of graphite differs from that of diamond, and how this affects its properties C4.3.6 explain the properties of diamond and graphite in terms of their structures and bonding, include melting point, hardness and (for graphite) conductivity and lubricating action  C5.3.5 recall that silicon, oxygen and aluminium are very abundant elements in the crust NA  C5.3.6 interpret data about the abundances of elements in rocks NA 
C6.1.1 balance unbalanced symbol equations use the and symbols of common elements and compounds and the principle of conservation of mass to write formulae and balanced chemical equations and ionic equations  C6.1.1 write balanced equations, including the state symbols (s), (l), (g) and (aq), to describe the characteristic reactions of acids and other reactions when given appropriate information C3.2.3 use the names and symbols of common elements and compounds and the principle of conservation of mass to write formulae and balanced chemical equations and ionic equations  C6.1.1 recall the state symbols (s), (l), (g) and (aq) and understand their use in equations C2.4.4 describe the physical states of products and reactants using state symbols (s, l, g and aq)  C6.1.1 recall that the reaction of an acid with an alkali to form a salt is a neutralisation reaction C5.4.4 describe neutralisation as acid reacting with alkali to form a salt plus including the common laboratory acids hydrochloric acid, nitric acid and sulfuric acid and the common alkalis, the hydroxides of sodium, potassium and calcium  C6.1.1 explain that acidic compounds produce aqueous hydrogen ions, H+(aq), when they dissolve in water C5.4.5 recall that acids form hydrogen ions when they dissolve in water and solutions of alkalis contain hydroxide ions  C6.1.1 explain that alkaline compounds produce aqueous hydroxide ions, when they dissolve in water C5.4.5 recall that acids form hydrogen ions when they dissolve in water and solutions of alkalis contain hydroxide ions  C6.1.1 down the name of the salt produced given the names of the acid and alkali C5.4.4 describe neutralisation as acid reacting with alkali to form a salt plus including the common laboratory acids hydrochloric acid, nitric acid and sulfuric acid and the common alkalis, the hydroxides of sodium, potassium and calcium 
C6.2.12 substitute results in a given mathematical formula to interpret titration results quantitatively C5.4.9 explain the relationship between the volume of a solution of known concentration of a substance and the volume or concentration of another substance that react completely together (separate science only)  C6.2.13 understand why it is important to control the rate of a chemical reaction (to include safety and economic factors) NA  C6.2.14 explain what is meant by the term ‘rate of chemical reaction’ C6.2.1 describe the effect on rate of reaction of changes in temperature, concentration, pressure, and surface area  C6.2.15 describe methods for following the rate of a reaction (for example, by collecting a gas, weighing the reaction mixture or observing the formation or loss of a colour or precipitate) C6.2.7 suggest practical methods for determining the rate of a given reaction including: PAG8 for reactions that produce gases: i. gas syringes or collection over water can be used to measure the volume of gas produced ii. mass change can be followed using a balance measurement of physical factors: iii. colour change iv. formation of a precipitate  C6.2.16 interpret results from experiments that investigate of reactions C6.2.8 interpret rate of reaction graphs  C6.2.17 understand how reaction rates vary with the size of solid particles, the concentration of solutions of chemicals and the temperature of the reaction mixture C6.2.1 describe the effect on rate of reaction of changes in temperature, concentration, pressure, and surface area  C6.2.18 understand that catalysts speed up chemical reactions while not being used up in the reaction C6.2.4 describe the characteristics of catalysts and their effect on rates of reaction  C6.2.19 interpret information about the control of rates of reaction in chemical synthesis C6.2.9 interpret graphs of reaction conditions versus rate (separate science only) 
C6.2.20 use simple ideas about collisions to explain how chemical reactions take place C6.2.2 explain the effects on rates of reaction of changes in temperature, concentration and pressure in terms of frequency and energy of collision between particles  C6.2.21 use simple collision theory and ideas about collision frequency to explain how rates of reaction depend on the size of solid particles and on the concentration of solutions of dissolved chemicals C6.2.2 explain the effects on of reaction of changes in temperature, concentration and pressure in terms of frequency and energy of collision between particles  C7.1.1 understand and use the ‘bulk’ (made on a large scale) and ‘fine’ (made on a small scale) in the context of the chemical industry NA  C7.1.2 recall examples of chemicals made on a scale (ammonia, sulfuric acid, sodium hydroxide, phosphoric acid) and examples of chemicals made on a small scale (drugs, food additives, fragrances) NA  C7.1.3 interpret information the work done by people who make chemicals NA  C7.1.4 understand that the development of new chemical products or processes requires an extensive programme of research and development (for example, catalysts for new processes) NA  C7.1.5 recall that governments have strict regulations to control chemical processes as well as the storage and transport of chemicals to protect people and the environment NA 
C7.2.7 represent chemical reactions by word equations C3.2.3 use the names and symbols of common elements and compounds and the principle of conservation of mass to write formulae and balanced chemical equations and ionic equations  C7.2.8 interpret symbol equations, including the number of atoms of each element, the number of molecules of each element or covalent compound and the number of ‘formulas’ of ionic compounds, in reactants and products C3.2.3 use the names and symbols of common elements and compounds and the principle of conservation of mass to write formulae and balanced chemical equations and ionic equations  C7.2.9 represent chemical reactions by balanced equations, including state symbols C2.4.4 describe the physical states of products and reactants using state symbols (s, l, g and aq)  C7.2.10 recall the names, molecular formulae and structural formulae of methanol and ethanol C3.4.17 name and draw the structural formulae, fully displayed formulae, of the first four members of the straight chain alkanes and alkenes, alcohols and carboxylic acids (separate science only)  C7.2.11 recall two uses of methanol and two uses of ethanol NA  C7.2.12 recognise the formulae of alcohols C3.4.18 predict the formulae and structures of products of reactions (combustion, addition across a double bond and oxidation of alcohols to carboxylic acids) of the first four and other given members of these homologous series (separate science only)  C7.2.13 understand that the characteristic properties of alcohols are due to the presence of the –OH functional group C3.4.18 predict the formulae and structures of products of reactions (combustion, addition across a double bond and oxidation of alcohols to carboxylic acids) of the first four and other given members of these homologous series (separate science only) 
C7.2.14 recall how ethanol compares in its physical properties with water and with alkanes C3.4.18 predict the formulae and structures of products of reactions (combustion, addition across a double bond and oxidation of alcohols to carboxylic acids) of the first four and other given members of these homologous series (separate science only)  C7.2.15 understand that alcohols burn in air to produce carbon dioxide and water because of the presence of a hydrocarbon chain C3.4.18 predict the formulae and structures of products of reactions (combustion, addition across a double bond and oxidation of alcohols to carboxylic acids) of the first four and other given members of these homologous series (separate science only)  C7.2.16 recall the reaction of alcohols with sodium and how this compares with the reactions of water and alkanes with sodium NA  C7.2.17 understand why there is a limit to the concentration of ethanol solution that can be made by fermentation NA  C7.2.18 understand how ethanol solution can be concentrated by distillation and that this can be used to make products such as whisky and brandy NA  C7.2.19 understand the optimum conditions for making ethanol by fermentation of with yeast, taking into consideration temperature and pH NA  C7.2.20 understand how genetically modified E. coli bacteria can be used to convert waste biomass from a range of sources into ethanol and recall the optimum conditions for the process NA  C7.2.21 recall in outline the synthetic route for converting ethane (from oil or natural gas) into ethanol (via ethene) NA  C7.2.22 interpret data about the different processes involved in the production of ethanol, and evaluate their sustainability NA 