Processes

of the planet

Applies understanding of models of matter to explain changes
of state in terms of energy being gained or lost by a substance.

A simple experiment can be carried out to identify chemicals based on their melting point (salol, stearic acid and salt).

The effect of heat on chocolate and an egg white can be compared as described in the Practical Chemistry website from the Royal Society of Chemistry and the Nuffield Foundation.

Knows that elements are organised in the Periodic Table by atomic number, each with its own unique symbol, and that elements with similar chemical properties are placed together in vertical groups.

Identifies and names the groups ‘alkali metals’, ‘halogens’ and ‘noble gases’ and describes their reactivity.

Chemical properties can be shown by demonstration of the alkali metals with water, discussion of the noble gases’ lack of reactivity or by showing videos of reactions of the halogens.

Elements can be tested for electrical conductivity.

Constructs names of two-element compounds which are derived from the names of the elements, from which it is formed, with a suffix of-ide.

Constructs word equations for simple reactions, for example, carbon reacting with oxygen: carbon + oxygen   à  carbon dioxide.

Gives examples of pure substances and mixtures from everyday life.

Air can be used as an example of a mixture of gases and the gas tests can be used to identify oxygen, carbon dioxide and nitrogen (nitrogen fails both tests). Calcium chloride can also be used to show the presence of water vapour.

Simple diagrams can be used to show pictorially the composition of an element, compound or mixture.

A mixture of for example copper carbonate and copper sulphate can be separated using solubility, filtration and evaporation. Simple methods such as flotation and magnetism can also be shown for some mixtures.

Everyday separation of mixtures can be investigated including water purification, distillation of alcohol and separation of metal waste before recycling.

Explains the link between the relative quantity of solute or solvent and changes in the concentration of a solution.

Everyday example such as nail varnish remover and dry cleaning can show the use of alternative solvents.

Saturated solutions of alum can be used to prepare large crystals whilst also revisiting the effect of temperature on solubility.

Investigates and describes the colour changes of indicators when added to acid/bases.

Investigates and describes the pH of some everyday substances.

Identifies substances as acidic (pH of less than 7), alkaline/basic (pH greater than 7) or neutral (equal to 7).

Investigates and describes what happens to the pH when an acid is added to an alkali/basic.

Learners should be familiar with the process of identifying an acid or alkali using indicators. Although this can be carried out practically using laboratory and household chemicals, it may be better for learners to make an indicator themselves. (e.g. red cabbage). Universal indicator should be used in order for learners to experience the full range of pH values.

Learners may have an appreciation that CO2 is a by-product of burning fossil fuels but another large contribution is made by cement manufacture required for new buildings.

Learners could investigate the effect of low pH drinks on teeth using pieces of bone, (the Sip Smart activity from the British Columbia Paediatric Society).

Positive uses of acids should also be investigated, e.g. acidity regulators in foodstuffs such as ethanoic acid (E260) and citric acid (E330). Benzoic acid (E210) is a preservative. HCl is used by the body for digestion; lightning storms supply much needed nitrates to the soil of rain forests.

Neutralisation reactions can be used to deal with the after effects of acid rain. Examples include the liming of fields in agriculture to reduce the pH of soil. Learners could discuss the clean-up of spilt chemicals and methods used to minimise risk. Everyday uses of neutralisation reactions may include stings, indigestion and teeth cleaning.

Finds the relationship between particle size, concentration temperature and catalysts and the rate of a reaction.

Explains how catalysts, including enzymes, can be used to speed up chemical reactions, and provides at least two everyday examples of reactions involving a catalyst.

Having discovered the signs of a chemical reaction, cognitive conflict can be given by discussion of physical changes.  A series of examples can be used to practice identifying the elements from which a compound was formed as well as simple chemical formulae. Card sorts and games can be used to reinforce these skills.

Investigates and discusses the relationship between a range of factors (for example, the combination of metal electrodes used, the electrolyte used, the electrolyte concentration, the distance between electrodes and surface area of electrodes) and the voltage produced by a simple chemical.

Demonstrate the lemon/orange battery.

Planning an investigation and each group identifies a different independent variable to investigate.

Present data/ information using an increasing range of ways, choosing appropriately from an extended range of tables, charts, diagrams and graphs and using suitable scales

Interpret and analyse the data and information and establish relationships between variables and link to the original hypothesis

Establish links between the findings and original questions and hypothesis or prediction. Use understanding of science concepts to explain the findings

Evaluate range of aspects of the investigation/enquiry including relevance and reliability of evidence

Communicate effectively in range of ways including orally and through scientific report writing

The use of neutralisation within divers tanks to increase dive time.

The use of metal carbonates in antacid tablets to relieve indigestion.

Impact of increased pollution on marine life.

Impact of fizzy drinks on dental health.

Possible investigation activities:

Effect of increasing temperature of the rate of reaction.

Effect of increasing concentration of the rate of reaction.

Effect of increasing surface area on the rate of reaction.

(All involving calcium carbonate and HCl)

Standard Investigation:

Factors affecting voltage produced by a simple chemical.