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GCSE ScienceBiology, chemistry and physics

GCSE required practicals, explained

Every AQA required practical, Edexcel core practical and OCR practical activity group, 32 practicals in all, with which boards have it, what you change, measure and keep the same, the method in short, a safety point, and where the marks go.

Written in our own words for pupils in England. Your teacher’s method may differ in the details, and that’s fine: the exam asks about the science, not one exact recipe.

Start with biologyHow practicals are examined

Biology · OsmosisVariables

How does the concentration of sugar solution affect the mass of potato cylinders?

  1. 1Change: the concentration of the solution
  2. 2Measure: the percentage change in mass
  3. 3Keep the same: size of cylinder, volume, time, temperature
  4. 4Safety: cut onto a tile, away from your fingers
Every practical, set out the same way

01 / How practicals are examinedAt least 15% of the marks

What the exam actually asks

You do the practicals in class, but the marks come in the written papers. Every board gives at least 15% of its science marks to practical work.

What each exam board calls its practicals
BoardWhat they’re calledHow they work
AQARequired practicals, numberedA fixed list for each course: 10 in Biology, 8 in Chemistry, 10 in Physics and 21 in Combined Science. Questions can ask about any of them.
Pearson EdexcelCore practicalsA fixed list: 8 in each separate science and 18 in Combined Science.
OCR (Gateway and Twenty First Century)Practical activity groups (PAGs)Groups of skills. Schools choose an experiment for each group, so the exam asks about the techniques rather than one set method. Twenty First Century also writes some methods into its content, and those can be asked about directly.

Show Working is independent and not affiliated with or endorsed by AQA, Pearson Edexcel or OCR. Board details are from each board’s own specification.

The words examiners look for

Independent variable
The one thing you change on purpose.
Dependent variable
The thing you measure to see the effect.
Control variables
Everything else you keep the same, so the test is fair.
Accurate
Close to the true value.
Precise
Repeat readings that are close to each other.
Repeatable and reproducible
Repeatable: you get similar results doing it again yourself. Reproducible: someone else, or another method, gets similar results.
Resolution
The smallest change an instrument can show, such as 1 mm on a ruler or 0.01 g on a balance.
Anomalous result
A reading that doesn’t fit the pattern. Check it, repeat it, and leave it out of the mean if it’s a mistake.
Random and systematic error
Random errors scatter readings either side of the true value; repeating and taking a mean helps. Systematic errors push every reading the same way, such as a balance that isn’t zeroed.

02 / Jump to a practical32 practicals

Biology

Looking at cells with a microscopeAntiseptics and antibiotics on bacteriaOsmosis in plant tissueFood testsEnzymes and pHLight intensity and photosynthesisReaction timeRate of respirationLight or gravity and seedling growthSampling with quadrats and transectsTemperature and the decay of milk

Chemistry

Making a pure, dry saltTitrationElectrolysis of solutionsTemperature changes in reactionsRates of reactionPaper chromatographyIdentifying ionsTesting and purifying waterpH change during neutralisationEnergy from burning alcoholsReactivity trends

Physics

Specific heat capacityThermal insulatorsResistance of a wire, and circuitsI–V characteristicsDensityForce and extension of a springForce, mass and accelerationWaves in a ripple tank and a solidReflection and refraction of lightInfrared radiation and surfaces

03 / Biology11 practicals

Biology required practicals

From microscopes to quadrats. Each card says which boards have it, and whether it’s in Combined Science or separate Biology only.

BiologyAQA, Edexcel and OCR

Looking at cells with a microscope

Make a slide of plant or animal cells, look at it under a light microscope, then draw and label what you see.

  • AQARequired practical 1 (Biology), 1 (Combined)
  • EdexcelCore practical, Biology and Combined Science
  • OCRPAG: microscopy, Biology and Combined Science
Method in short
  1. Peel a thin layer of onion skin and lay it flat in a drop of water on a slide.
  2. Add a drop of iodine solution to stain it, then lower a cover slip at an angle so no air bubbles get trapped.
  3. Start with the lowest power objective lens and focus with the coarse focusing knob.
  4. Switch to a higher power and sharpen the image with the fine focusing knob.
  5. Draw a few cells with a sharp pencil, label the cell wall, cytoplasm and nucleus, and note the magnification.
What you should find
Total magnification is the eyepiece lens magnification multiplied by the objective lens magnification. To find the real size of a cell, divide the size of the image by the magnification.
Stay safe
Iodine solution irritates eyes and stains skin, so wear eye protection. Handle slides and cover slips with care, as they break into sharp pieces.
Where marks go
Drawings should use clear single lines with no shading, and label lines drawn with a ruler that don’t cross.

BiologyAQA, Edexcel and OCR

Antiseptics and antibiotics on bacteria

Find out which antiseptic or antibiotic is best at stopping bacteria from growing.

  • AQARequired practical 2 (Biology only)
  • EdexcelCore practical, Biology only
  • OCRPAG: microbiological techniques, Biology and Combined Science
You change
The antiseptic or antibiotic on each paper disc.
You measure
The width of the clear zone around each disc, where bacteria haven’t grown.
Keep the same
The size of the discs, how long they soak, the bacteria, the agar, and the temperature and time of incubation.
Method in short
  1. Pass an inoculating loop through a Bunsen flame to sterilise it, and let it cool.
  2. Spread bacteria evenly over the agar in a Petri dish.
  3. Put discs soaked in each substance on the agar, plus one soaked in sterile water as a control.
  4. Tape the lid on with a few strips, label the dish and incubate it upside down at no more than 25 °C.
  5. After about two days, measure the clear zone around each disc and work out its area.
What you should find
The bigger the clear zone, the better that substance is at killing the bacteria or stopping them growing.
Stay safe
Keep everything sterile and never open the dish after incubating it. Incubating at 25 °C or below makes it less likely that bacteria harmful to people will grow.
Where marks go
Don’t seal the lid all the way round: oxygen needs to get in, so that harmful bacteria that grow without oxygen don’t take over.

BiologyAQA, Edexcel and OCR

Osmosis in plant tissue

Find out how the concentration of a sugar or salt solution affects the mass of pieces of potato.

  • AQARequired practical 3 (Biology), 2 (Combined)
  • EdexcelCore practical, Biology and Combined Science
  • OCRPAG: transport in and out of cells, Biology only
You change
The concentration of the solution, including one tube of pure water.
You measure
The mass of each potato cylinder before and after, turned into a percentage change in mass.
Keep the same
The size of the cylinders, the volume of solution, the time they are left and the temperature.
Method in short
  1. Cut cylinders of potato with a cork borer and trim them to the same length.
  2. Blot each one dry, weigh it on a balance and write the mass down.
  3. Put one cylinder in each tube of solution and leave them all for the same time.
  4. Take them out, blot them dry in the same way and weigh them again.
  5. Work out the percentage change in mass and plot it against the concentration.
What you should find
In weak solutions the potato gains mass, because water moves into the cells by osmosis. In strong solutions it loses mass. Where the line crosses zero, the solution matches the concentration inside the cells.
Stay safe
Cut onto a tile, with the blade moving away from your fingers.
Where marks go
Use percentage change, not just the change in mass, because the cylinders don’t all start at exactly the same mass.

BiologyAQA, Edexcel and OCR

Food tests

Find out which food molecules (starch, sugars, proteins and fats) are in a food.

  • AQARequired practical 4 (Biology), 3 (Combined)
  • EdexcelCore practical, Biology only
  • OCRPAG: testing for biological molecules, Biology only
Method in short
  1. Grind the food with a little distilled water, then filter it to get a solution.
  2. Starch: add iodine solution. It turns from orange-brown to blue-black if starch is there.
  3. Sugars: add Benedict’s solution and heat in a hot water bath for a few minutes. Blue turns green, yellow or brick-red if a reducing sugar such as glucose is there.
  4. Protein: add Biuret solution. Blue turns purple if protein is there.
  5. Fats (the emulsion test, which Edexcel names): shake the food with ethanol, then pour the liquid into water. A cloudy white layer means fat is there. Some schools use Sudan III instead, which stains fat red.
What you should find
Each test is either positive or negative. With Benedict’s, the colour also hints at how much sugar there is, from green for a little to brick-red for a lot.
Stay safe
Wear eye protection. Heat Benedict’s in a water bath, never over a flame, and keep ethanol well away from flames.
Where marks go
Always give the colour before and after, and remember that Benedict’s needs heating while the others don’t.

BiologyAQA, Edexcel and OCR

Enzymes and pH

Find out how pH affects how quickly the enzyme amylase breaks down starch.

  • AQARequired practical 5 (Biology), 4 (Combined)
  • EdexcelCore practical, Biology and Combined Science
  • OCRPAG: rates of enzyme-controlled reactions (pH or another factor, such as temperature), Biology and Combined Science
You change
The pH, using a different buffer solution each time.
You measure
The time until all the starch has gone.
Keep the same
The temperature (in a water bath) and the volumes and concentrations of amylase and starch.
Method in short
  1. Put a drop of iodine solution in each dip of a spotting tile.
  2. Warm the amylase, the starch and a buffer solution in a water bath.
  3. Mix them and start the stopwatch.
  4. Every 30 seconds (AQA’s interval), put a drop of the mixture onto a fresh drop of iodine.
  5. When the iodine stays orange-brown, the starch has gone: write down the time. Repeat at other pH values.
What you should find
The starch goes fastest at the enzyme’s best (optimum) pH. Far from it, the active site changes shape, the enzyme is denatured and starch no longer fits.
Stay safe
Wear eye protection, as iodine solution and enzyme solutions can irritate.
Where marks go
You only know the time to the nearest sampling interval, so testing more often gives a more precise result.

BiologyAQA, Edexcel and OCR

Light intensity and photosynthesis

Find out how light intensity affects the rate of photosynthesis in pondweed or algal balls.

  • AQARequired practical 6 (Biology), 5 (Combined)
  • EdexcelCore practical, Biology and Combined Science (algal balls in hydrogencarbonate indicator, which changes colour as carbon dioxide is taken in)
  • OCRPAG: photosynthesis, Biology and Combined Science
You change
The distance of the lamp from the pondweed.
You measure
The number of oxygen bubbles given off in a minute, or the volume of gas collected.
Keep the same
The temperature (an LED lamp gives off little heat), the amount of carbon dioxide (the same sodium hydrogencarbonate solution), and the same piece of pondweed.
Method in short
  1. Put pondweed in a boiling tube of water with a little sodium hydrogencarbonate.
  2. Measure the distance from the lamp to the pondweed with a ruler.
  3. Leave the pondweed a few minutes to settle at that light level.
  4. Count the bubbles given off in one minute, and repeat to find a mean.
  5. Move the lamp to a new distance and repeat.
What you should find
The closer the lamp, the faster the bubbles, until something else such as carbon dioxide or temperature limits the rate. On Higher, you also need to know that light intensity is proportional to 1 ÷ distance² (the inverse square law).
Stay safe
Lamps get hot. Keep water away from the lamp and the plug, and mop up spills straight away.
Where marks go
Bubbles vary in size, so collecting the gas in a syringe or a measuring cylinder is more accurate than counting.

BiologyAQA

Reaction time

Find out how a factor, such as practice or a caffeine drink, affects how quickly a person reacts.

  • AQARequired practical 7 (Biology), 6 (Combined)
You change
The factor you are testing.
You measure
How far a dropped ruler falls before it is caught, turned into a reaction time with a table.
Keep the same
The person, the hand they use and where the ruler starts.
Method in short
  1. Your partner holds a ruler upright, with the zero mark level with the top of your thumb.
  2. They let go without warning, and you catch it as fast as you can.
  3. Read the distance at the top of your thumb.
  4. Repeat several times and work out a mean.
  5. Change the factor, then repeat the whole test.
What you should find
A shorter distance means a faster reaction time. Practice usually makes people faster.
Stay safe
Low risk. If you test a caffeine drink, check that no one taking part needs to avoid caffeine.
Where marks go
People get tired or improve with practice, so things are hard to keep the same: repeat and take a mean.

BiologyEdexcel and OCR

Rate of respiration

Find out how temperature affects the rate of respiration in small living things, such as woodlice or germinating peas.

  • EdexcelCore practical, Biology and Combined Science
  • OCRPAG: physiology, responses and respiration, Biology only (OCR’s example is exercise and pulse rate, so a respirometer is just one option)
You change
The temperature of the water bath.
You measure
How far the coloured liquid moves along the capillary tube in a set time.
Keep the same
The number or mass of organisms, the amount of soda lime and the time.
Method in short
  1. Put soda lime in a boiling tube to absorb carbon dioxide, then a gauze on top.
  2. Put the organisms on the gauze and fit a capillary tube with a drop of coloured liquid.
  3. Stand the tube (a respirometer) in a water bath at the first temperature.
  4. Measure how far the liquid moves in a set time, such as five minutes.
  5. Repeat at other temperatures.
What you should find
The organisms take in oxygen and the carbon dioxide they give out is absorbed, so the air in the tube shrinks and the liquid moves towards them. The faster it moves, the faster they are respiring.
Stay safe
Soda lime is corrosive, so wear eye protection and don’t touch it. Handle animals gently and return them to where you found them.
Where marks go
Set up a control tube with glass beads instead of organisms, to show that the movement is caused by the living things.

BiologyAQA and OCR

Light or gravity and seedling growth

Find out how light from one side, or gravity, affects the way young seedlings grow.

  • AQARequired practical 8 (Biology only)
  • OCRTwenty First Century Biology only: not a PAG, but you may be asked to describe light experiments on shoots
You change
The direction of the light (or which way up the seedlings are).
You measure
The direction the shoots or roots grow in, and how long they get.
Keep the same
The type and number of seeds, the water, the temperature and the time.
Method in short
  1. Grow cress or bean seeds on damp cotton wool in Petri dishes.
  2. Put one dish in a box lit from one side only, and one in even light as a control.
  3. For gravity, turn some seedlings on their side, kept in the dark.
  4. After a few days, measure the shoots and roots and make labelled drawings to show which way they are growing.
What you should find
Shoots grow towards light (phototropism), because the hormone auxin builds up on the shaded side and makes cells there grow longer. Roots grow downwards with gravity (gravitropism).
Stay safe
Low risk. Wash your hands after handling seeds and cotton wool.
Where marks go
Use the right name for each response, phototropism or gravitropism, and say what auxin does.

BiologyAQA, Edexcel and OCR

Sampling with quadrats and transects

Estimate the size of a population with random quadrats, and see how a species’ spread changes along a transect.

  • AQARequired practical 9 (Biology), 7 (Combined)
  • EdexcelCore practical, Biology and Combined Science
  • OCRPAG: sampling techniques, Biology and Combined Science
You change
Where the quadrat goes along the transect (and so a factor such as light or trampling).
You measure
The number of plants of one species, or the percentage of the quadrat they cover.
Keep the same
The size of the quadrat and the way you count.
Method in short
  1. Lay two tape measures at right angles to make a grid over the area.
  2. Use random numbers to pick coordinates, place a quadrat there and count the species.
  3. Do this for many quadrats and find the mean number per quadrat.
  4. Scale up: mean per square metre × area in square metres gives the estimated population.
  5. For a transect, lay a tape across the area and place a quadrat at regular points along it.
What you should find
Random quadrats give a fair estimate of a whole population. A transect shows how numbers change from one place to another, for example from shade into sun.
Stay safe
Check the site for hazards such as water, steep ground or stinging plants, and wash your hands afterwards.
Where marks go
Random placing avoids picking spots by eye, and more quadrats give a more reliable estimate.

BiologyAQA

Temperature and the decay of milk

Find out how temperature affects how fast milk goes off, by following the change in pH.

  • AQARequired practical 10 (Biology only)
You change
The temperature of the water bath.
You measure
The time for the pH to fall, shown by an indicator changing colour.
Keep the same
The volumes of milk, enzyme (lipase) and sodium carbonate solution, and the amount of indicator.
Method in short
  1. Put milk, sodium carbonate solution and a few drops of an indicator that is pink in alkali into a test tube.
  2. Warm it and a tube of lipase in a water bath to the chosen temperature.
  3. Add the lipase and start the stopwatch.
  4. Stop the clock when the pink colour disappears.
  5. Repeat at other temperatures.
What you should find
Lipase breaks fats into fatty acids, which lower the pH. It works faster as the temperature rises, up to its best temperature, then slows as the enzyme is denatured.
Stay safe
Never drink the milk. Wear eye protection, as sodium carbonate solution irritates the eyes.
Where marks go
Judging the end of a colour change is tricky, so compare against a tube of the final colour.

Back to the list · GCSE Biology questions

04 / Chemistry11 practicals

Chemistry required practicals

From making salts to titrations. Watch for the ones that are separate Chemistry only.

ChemistryAQA, Edexcel and OCR

Making a pure, dry salt

Make crystals of a soluble salt, such as copper sulfate, from an insoluble base and an acid.

  • AQARequired practical 1 (Chemistry), 8 (Combined)
  • EdexcelCore practical, Chemistry and Combined Science (copper sulfate)
  • OCRPAG: production of salts, Chemistry and Combined Science
Method in short
  1. Warm some dilute sulfuric acid gently, without boiling it (AQA uses a Bunsen burner, Edexcel a water bath).
  2. Add copper oxide a little at a time, stirring, until no more dissolves (it is in excess).
  3. Filter the mixture to remove the leftover copper oxide.
  4. Heat the solution in an evaporating basin until crystals start to form at the edge (AQA uses a water bath or electric heater here, Edexcel a Bunsen burner).
  5. Leave it to cool and crystallise, then dry the crystals between filter papers or on a watch glass.
What you should find
Blue crystals of hydrated copper sulfate. The excess copper oxide makes sure all the acid has reacted.
Stay safe
Wear eye protection. Don’t heat the solution to dryness, as it can spit, and avoid skin contact with copper compounds.
Where marks go
Say why each step is there: excess base to use up all the acid, filtering to remove the excess, slow crystallising for bigger crystals.

ChemistryAQA, Edexcel and OCR

Titration

Find exactly how much acid neutralises a measured volume of alkali.

  • AQARequired practical 2 (Chemistry only)
  • EdexcelCore practical, Chemistry only
  • OCRPAG: titration, Chemistry only
Method in short
  1. Use a pipette and filler to put 25.0 cm³ of the alkali into a conical flask, and add a few drops of indicator.
  2. Fill a burette with acid and read it at eye level, from the bottom of the meniscus.
  3. Stand the flask on a white tile and add acid while swirling, slowing to drops near the end.
  4. Stop when the indicator just changes colour, and read the burette again.
  5. Do a rough run first, then repeat carefully until you have concordant titres (ones that agree closely, often within 0.10 cm³), and take their mean.
What you should find
The volume of acid used (the titre) is the final reading minus the first. On Higher, you use it to work out a concentration.
Stay safe
Wear eye protection. Fill the burette below eye level, and take the funnel out before you start.
Where marks go
Use an indicator with one sharp colour change, such as phenolphthalein or methyl orange. Universal indicator changes gradually, so it isn’t used.

ChemistryAQA, Edexcel and OCR

Electrolysis of solutions

Find out what forms at each electrode when a solution is split by electricity.

  • AQARequired practical 3 (Chemistry), 9 (Combined)
  • EdexcelCore practical, Chemistry and Combined Science (copper sulfate)
  • OCRPAG: electrolysis, Chemistry and Combined Science
Method in short
  1. Pour the solution into a beaker and dip in two inert (graphite) electrodes.
  2. Connect them to a low-voltage power supply and switch on.
  3. Watch each electrode for bubbles of gas or a coating of metal.
  4. Collect any gas in a small test tube and test it.
What you should find
At the negative electrode, the metal coats it if it is less reactive than hydrogen (copper, for example); otherwise hydrogen bubbles off, which burns with a squeaky pop. At the positive electrode, a halogen forms if the solution has halide ions; otherwise oxygen forms, which relights a glowing splint. Chlorine bleaches damp litmus paper.
Stay safe
Chlorine is toxic: keep the voltage low, run it for a short time and work in a well-ventilated room.
Where marks go
Edexcel also uses copper electrodes in copper sulfate: the positive electrode loses mass and the negative one gains it.

ChemistryAQA and OCR

Temperature changes in reactions

Find out how a variable, such as the volume of alkali added to an acid, affects the temperature change.

  • AQARequired practical 4 (Chemistry), 10 (Combined)
  • OCRTwenty First Century Chemistry only: not a PAG, but you may be asked how to test whether a reaction is exothermic or endothermic
You change
The volume of sodium hydroxide added to the acid.
You measure
The highest temperature reached after each addition.
Keep the same
The volume and concentration of the acid, and the starting temperature.
Method in short
  1. Put 30 cm³ of dilute hydrochloric acid in a polystyrene cup, standing in a beaker so it doesn’t tip.
  2. Measure the starting temperature.
  3. Add 5 cm³ of sodium hydroxide solution, stir and record the highest temperature.
  4. Keep adding 5 cm³ at a time, recording the temperature each time.
  5. Plot temperature against the volume added.
What you should find
The temperature rises (the reaction is exothermic) until the acid is all used up, then falls as cooler alkali is added. Two lines of best fit meet at the highest temperature.
Stay safe
Wear eye protection: even dilute sodium hydroxide can damage eyes.
Where marks go
The polystyrene cup and a lid cut the energy lost to the surroundings, which makes the result more accurate.

ChemistryAQA, Edexcel and OCR

Rates of reaction

Find out how concentration (or temperature) affects the rate of a reaction, measured two different ways.

  • AQARequired practical 5 (Chemistry), 11 (Combined)
  • EdexcelCore practical, Chemistry and Combined Science (marble chips and acid; thiosulfate at different temperatures)
  • OCRPAG: measuring rates of reaction, Chemistry and Combined Science
You change
The concentration of the acid (or of the sodium thiosulfate), or the temperature.
You measure
The volume of gas made at regular times, or the time for a cross under the flask to disappear.
Keep the same
The volumes, the temperature (or concentration), the mass and size of any solid, and the cross and the person watching it.
Method in short
  1. Gas method: react magnesium ribbon or marble chips with acid and collect the gas in a gas syringe or an upside-down measuring cylinder.
  2. Read the volume of gas every 10 seconds.
  3. Cloudiness method: mix sodium thiosulfate and hydrochloric acid in a flask standing on a drawn cross.
  4. Time how long it takes until you can no longer see the cross through the solution.
  5. Repeat with different concentrations.
What you should find
The higher the concentration, the faster the reaction, because particles collide more often. The sulfur that forms in the thiosulfate reaction is what makes the solution cloudy.
Stay safe
Wear eye protection. The thiosulfate reaction gives off sulfur dioxide, which can trigger asthma, so work in a well-ventilated room.
Where marks go
Judging when the cross vanishes depends on the person, so keep the same person, or use a light sensor.

ChemistryAQA, Edexcel and OCR

Paper chromatography

Separate the coloured substances in an ink or food colouring, and work out their Rf values.

  • AQARequired practical 6 (Chemistry), 12 (Combined)
  • EdexcelCore practical, Chemistry and Combined Science (inks, with distillation)
  • OCRPAG: separation techniques, Chemistry and Combined Science
Method in short
  1. Draw a start line in pencil about 1 cm from the bottom of the paper.
  2. Put small spots of each ink on the line.
  3. Stand the paper in a beaker of solvent, with the solvent below the line, and cover the beaker.
  4. Take the paper out before the solvent reaches the top, and mark how far the solvent got.
  5. Rf = distance moved by the spot ÷ distance moved by the solvent.
What you should find
A pure substance gives one spot. A mixture gives two or more. A substance has the same Rf in the same solvent every time, which helps identify it.
Stay safe
If the solvent is flammable, such as ethanol, keep it away from flames.
Where marks go
Use pencil for the start line, because ink would run with the solvent. Keep the line above the solvent, or the spots dissolve into it.

ChemistryAQA, Edexcel and OCR

Identifying ions

Work out which positive and negative ions are in an unknown salt.

  • AQARequired practical 7 (Chemistry only)
  • EdexcelCore practical, Chemistry only
  • OCRPAG: identification of species, Chemistry only
Method in short
  1. Flame test: dip a clean wire loop in the solid and hold it in a blue Bunsen flame.
  2. Metal ions: add a few drops of sodium hydroxide solution and note the colour of any precipitate.
  3. Carbonate: add dilute acid. Bubbles of gas that turn limewater milky show carbonate.
  4. Halides: add dilute nitric acid, then silver nitrate solution, and note the colour of the precipitate.
  5. Sulfate: add dilute hydrochloric acid, then barium chloride solution. A white precipitate shows sulfate.
What you should find
Flame colours: lithium crimson, sodium yellow, potassium lilac, calcium orange-red and copper green (Edexcel says lithium red and copper blue-green; OCR doesn’t print colours). With sodium hydroxide: copper(II) blue, iron(II) green, iron(III) brown. With silver nitrate: chloride white, bromide cream, iodide yellow.
Stay safe
Wear eye protection. Sodium hydroxide is corrosive, silver nitrate stains skin and barium chloride is toxic, so use small amounts.
Where marks go
Clean the wire loop in acid between flame tests, or one metal’s colour can hide another’s.

ChemistryAQA, Edexcel and OCR

Testing and purifying water

Analyse water samples, then make pure water by distillation.

  • AQARequired practical 8 (Chemistry), 13 (Combined)
  • EdexcelSimple distillation is part of the inks core practical
  • OCRPAG: distillation, Chemistry and Combined Science (any mixture, such as ink or salty water)
Method in short
  1. Test the pH of each sample with universal indicator or a pH meter.
  2. Evaporate a measured volume in a weighed evaporating basin, then weigh it again to find the mass of dissolved solids.
  3. Distil a sample: heat it so the water boils, cool the steam in a condenser and collect the liquid.
  4. Check the distilled water: pure water has no solids left when evaporated and boils at 100 °C.
What you should find
Salty or impure water leaves solids behind when it evaporates. Distilled water is pure, so it leaves nothing.
Stay safe
Hot apparatus and steam can burn. Add anti-bumping granules so the liquid boils smoothly, and never heat the flask dry.
Where marks go
Distillation works because the water boils off and condenses back to a liquid in the condenser, while the dissolved salts stay behind in the flask.

ChemistryEdexcel

pH change during neutralisation

Follow how the pH changes as calcium hydroxide is added to dilute hydrochloric acid.

  • EdexcelCore practical, Chemistry and Combined Science
You change
The mass of calcium hydroxide added.
You measure
The pH, with universal indicator paper or a pH meter.
Keep the same
The volume and concentration of the acid, and the mass added each time.
Method in short
  1. Measure a set volume of dilute hydrochloric acid into a beaker.
  2. Add a small, weighed portion of calcium hydroxide and stir.
  3. Dip a glass rod in the mixture, touch it on universal indicator paper and match the colour to the pH chart.
  4. Repeat, adding a portion at a time, and plot pH against total mass added.
What you should find
The pH starts low and rises slowly, then jumps past neutral once nearly all the acid has reacted, and levels off above 7 as extra calcium hydroxide is left over.
Stay safe
Wear eye protection: calcium hydroxide can damage eyes.
Where marks go
A pH meter gives a more precise reading than matching colours on indicator paper.

ChemistryEdexcel

Energy from burning alcohols

Compare how much the water warms up when different alcohols are burned.

  • EdexcelCore practical, Chemistry only
You change
The alcohol: ethanol, propanol, butanol or pentanol.
You measure
The mass of alcohol burned to warm the water.
Keep the same
The volume of water, the can, the distance from flame to can, and the set temperature rise.
Method in short
  1. Weigh a spirit burner of alcohol with its cap on.
  2. Put a measured volume of water in a copper can clamped above the burner, and take its temperature.
  3. Light the burner and stir the water until its temperature has risen by a set amount.
  4. Put the cap on to put the flame out, then weigh the burner again.
  5. Repeat with each alcohol.
What you should find
Compare the temperature rise for each gram of alcohol burned. The longer the alcohol’s carbon chain, the more the water warms up for each gram.
Stay safe
Alcohols are highly flammable. Keep the bottles closed and well away from flames, and never refill a burner that is alight or still hot.
Where marks go
A lot of energy heats the air instead of the water, so a draught shield and a lid on the can make the results more accurate.

ChemistryOCR

Reactivity trends

Show that halogens get less reactive down Group 7, using displacement reactions.

  • OCRPAG: reactivity trend, Chemistry only (schools choose the activity; halogen displacement is a common one)
Method in short
  1. Put a few drops of potassium chloride, bromide and iodide solution in separate dips of a spotting tile.
  2. Add a few drops of chlorine water to each, and look for a colour change.
  3. Repeat with bromine water, then with iodine solution.
What you should find
Chlorine displaces bromine and iodine; bromine displaces iodine; iodine displaces neither. So reactivity goes down the group.
Stay safe
Halogen solutions give off harmful vapours: use small amounts in a well-ventilated room and wear eye protection.
Where marks go
A more reactive halogen pushes a less reactive one out of its compound, which shows up as a change of colour.

Back to the list · GCSE Chemistry questions

05 / Physics10 practicals

Physics required practicals

From specific heat capacity to waves. Most physics practicals are on every board, with small differences in the details.

PhysicsAQA, Edexcel and OCR

Specific heat capacity

Find how much energy it takes to warm 1 kg of a material by 1 °C.

  • AQARequired practical 1 (Physics), 14 (Combined)
  • EdexcelCore practical, Physics and Combined Science (water heated with an immersion heater, plus a graph for melting ice)
  • OCRPAG: energy, Physics and Combined Science
You change
The energy put in by the heater (it goes up with time).
You measure
The temperature of the block.
Keep the same
The mass of the block and the material it is made of.
Method in short
  1. Weigh the metal block, then put a heater and a thermometer into its holes.
  2. Wrap the block in insulation.
  3. Connect the heater to a joulemeter (or an ammeter and voltmeter) and a power supply.
  4. Record the temperature and the energy every minute for about ten minutes.
  5. Plot temperature against energy and use the gradient to work out the specific heat capacity.
What you should find
Specific heat capacity = energy ÷ (mass × temperature change). Your value usually comes out a bit too high, because some energy escapes to the surroundings.
Stay safe
The heater and block get very hot: don’t touch them, and let them cool before packing away.
Where marks go
Insulation cuts energy losses. A drop of water or oil in the thermometer hole gives better contact.

PhysicsAQA

Thermal insulators

Compare how well different materials keep hot water warm.

  • AQARequired practical 2 (Physics only)
You change
The insulating material (or how thick it is).
You measure
The temperature of the water every two minutes.
Keep the same
The volume and starting temperature of the water, the size of the beaker and the time.
Method in short
  1. Wrap beakers in different materials, leaving one unwrapped as a control.
  2. Pour the same volume of hot water into each and put a lid on.
  3. Record the temperature every two minutes for about twenty minutes.
  4. Plot cooling curves (temperature against time) for each material.
What you should find
The best insulator gives the smallest temperature drop in the same time.
Stay safe
Hot water scalds. Pour carefully, and stand the beakers where they can’t be knocked over.
Where marks go
Start each beaker at the same temperature, or the comparison isn’t fair.

PhysicsAQA, Edexcel and OCR

Resistance of a wire, and circuits

Find how the length of a wire affects its resistance, and how resistors combine in series and in parallel.

  • AQARequired practical 3 (Physics), 15 (Combined)
  • EdexcelCore practical, Physics and Combined Science (series and parallel)
  • OCRPAG: series and parallel circuits (Physics) and circuits (Combined); OCR’s example compares bulbs in series and parallel
You change
The length of wire between the crocodile clips.
You measure
The current and the potential difference, to work out resistance.
Keep the same
The type and thickness of the wire, and its temperature.
Method in short
  1. Tape the wire along a metre ruler and connect it with crocodile clips.
  2. Put an ammeter in series with the wire and a voltmeter in parallel across the length being tested.
  3. Record the current and potential difference for different lengths.
  4. Work out resistance = potential difference ÷ current for each length.
  5. Plot resistance against length.
What you should find
Resistance is directly proportional to length: a straight line through the origin (if it misses the origin slightly, the clips and leads are adding a little resistance). Adding resistors in series raises the total resistance; adding them in parallel lowers it.
Stay safe
The wire can get hot. Keep the potential difference low and switch off between readings.
Where marks go
Switching off between readings stops the wire warming up, since a hotter wire has more resistance.

PhysicsAQA, Edexcel and OCR

I–V characteristics

Find how the current through a component changes with the potential difference across it.

  • AQARequired practical 4 (Physics), 16 (Combined)
  • EdexcelCore practical, Physics and Combined Science (resistor and filament lamp)
  • OCRPAG: circuit components (Physics) and circuits (Combined)
You change
The potential difference across the component, using a variable resistor.
You measure
The current through it.
Keep the same
The component (and, for a resistor, its temperature).
Method in short
  1. Connect the component in series with an ammeter and a variable resistor.
  2. Put a voltmeter in parallel across the component.
  3. Adjust the variable resistor and record pairs of current and potential difference.
  4. Swap the power supply connections round and repeat for negative values.
  5. Plot current against potential difference.
What you should find
A resistor at constant temperature gives a straight line through the origin. A filament lamp gives a curve, because its resistance rises as it gets hotter. A diode (AQA, and often OCR) lets current through in one direction only.
Stay safe
Filament lamps get hot. Don’t touch them while they are on.
Where marks go
A straight line through the origin means current is directly proportional to potential difference.

PhysicsAQA, Edexcel and OCR

Density

Find the density of regular solids, irregular solids and liquids.

  • AQARequired practical 5 (Physics), 17 (Combined)
  • EdexcelCore practical, Physics and Combined Science
  • OCRPAG: materials, Physics and Combined Science
Method in short
  1. Regular solid: measure its sides with a ruler or calipers, work out its volume, and weigh it.
  2. Irregular solid: fill a displacement (eureka) can until water drips from the spout, lower the object in and collect the water that spills out in a measuring cylinder.
  3. Liquid: weigh an empty measuring cylinder, add a measured volume of liquid and weigh it again.
  4. Density = mass ÷ volume.
What you should find
The volume of water pushed out of the can equals the volume of the object.
Stay safe
Wipe up spilled water so no one slips, and lower heavy objects in gently.
Where marks go
Read the measuring cylinder at eye level, from the bottom of the meniscus.

PhysicsAQA, Edexcel and OCR

Force and extension of a spring

Find how the extension of a spring depends on the force stretching it.

  • AQARequired practical 6 (Physics), 18 (Combined)
  • EdexcelCore practical, Physics and Combined Science (with work done)
  • OCRPAG: forces, Physics and Combined Science
You change
The weight hung on the spring.
You measure
The extension: the new length minus the original length.
Keep the same
The spring, and the point on it you measure from.
Method in short
  1. Hang the spring from a clamp, with a metre ruler held upright beside it.
  2. Measure the length of the spring with no weights on it.
  3. Add a 1 N weight at a time and measure the new length each time.
  4. Work out each extension.
  5. Plot force against extension.
What you should find
Extension is proportional to force (a straight line through the origin) until the limit of proportionality. The gradient of that straight part is the spring constant.
Stay safe
Wear eye protection in case the spring snaps, and keep your feet clear of falling weights. Clamp the stand to the bench.
Where marks go
Use a pointer on the spring and read the ruler at eye level to avoid parallax errors.

PhysicsAQA, Edexcel and OCR

Force, mass and acceleration

Find how the force on a trolley, and its mass, affect its acceleration.

  • AQARequired practical 7 (Physics), 19 (Combined)
  • EdexcelCore practical, Physics and Combined Science (a trolley down a ramp, with masses added)
  • OCRPAG: motion, Physics and Combined Science (OCR’s example is a trolley down a ramp)
You change
The pulling force (or the mass of the trolley).
You measure
The acceleration, with light gates or by timing over a measured distance.
Keep the same
The total mass when you change the force, the force when you change the mass, and the track.
Method in short
  1. Pull a trolley along the bench with a string over a pulley, attached to a hanging mass.
  2. Use light gates to measure its speed at two points and the time between them.
  3. Work out the acceleration from the change in speed ÷ time.
  4. To change the force, move masses from the trolley to the hanger, so the total mass stays the same.
  5. Repeat for each force.
What you should find
Acceleration is proportional to the resultant force, and gets smaller as the mass gets bigger (force = mass × acceleration).
Stay safe
Put something soft under the hanging masses and stop the trolley before it runs off the bench.
Where marks go
Moving masses from trolley to hanger keeps the total mass being accelerated the same, so only the force changes.

PhysicsAQA, Edexcel and OCR

Waves in a ripple tank and a solid

Measure the frequency, wavelength and speed of waves on water and in a solid.

  • AQARequired practical 8 (Physics), 20 (Combined)
  • EdexcelCore practical, Physics and Combined Science
  • OCRPAG: measuring waves (Physics) and waves (Combined)
Method in short
  1. Ripple tank: shine a lamp through the water so the waves cast shadows on paper below.
  2. Measure across ten waves on the shadows and divide by ten to get the wavelength.
  3. Count the waves passing a point in ten seconds and divide by ten to get the frequency.
  4. Work out wave speed = frequency × wavelength.
  5. In a solid (AQA): a vibration generator shakes a stretched string. Read the frequency from the signal generator; one wavelength is two loops.
  6. In a solid (Edexcel): tap a metal rod with a hammer. The wavelength is twice the rod’s length, and an app or oscilloscope gives the frequency.
What you should find
Wave speed = frequency × wavelength. In one material the speed stays the same, so a higher frequency gives a shorter wavelength.
Stay safe
Keep water away from electrical equipment and mop up spills. Flashing (strobe) lights can trigger seizures in some people.
Where marks go
Measuring across several waves and dividing gives a more accurate wavelength than measuring one.

PhysicsAQA, Edexcel and OCR

Reflection and refraction of light

Find how light reflects off different surfaces and bends as it passes through a glass block.

  • AQARequired practical 9 (Physics only)
  • EdexcelCore practical, Physics and Combined Science (glass blocks)
  • OCRPAG: interactions of waves (Physics) and waves (Combined); OCR’s example uses a mirror and a prism
Method in short
  1. Put a glass block on paper and draw round it.
  2. Shine a thin ray from a ray box into the block, and mark the ray going in and coming out with crosses.
  3. Take the block away, join the crosses and draw the normal where the ray enters.
  4. Measure the angle of incidence and the angle of refraction with a protractor.
  5. Repeat for several angles, and for a mirror to compare reflection.
What you should find
Light slows down as it enters glass and bends towards the normal; it bends away from the normal as it leaves. For reflection, the angle of incidence equals the angle of reflection.
Stay safe
The ray box gets hot, and the room may be dim, so keep bags and stools out of the way.
Where marks go
Measure angles from the normal, the line at right angles to the surface, never from the surface itself.

PhysicsAQA and Edexcel

Infrared radiation and surfaces

Find how the colour and shininess of a surface affect the infrared radiation it gives out or takes in.

  • AQARequired practical 10 (Physics), 21 (Combined)
  • EdexcelCore practical, Physics only (beakers wrapped in different materials, with hot water cooling inside)
You change
The type of surface: matt black, shiny black, matt white or shiny silver.
You measure
The reading on an infrared detector held in front of each surface (or, for Edexcel, the temperature drop of the water in a set time).
Keep the same
The distance from detector to surface, and the temperature of the water (for Edexcel, the volume and starting temperature, with a lid on each).
Method in short
  1. Fill a Leslie cube (a metal box with a different surface on each side) with hot water.
  2. Hold an infrared detector the same distance from each face.
  3. Record the reading for each surface.
  4. Edexcel’s version: cover beakers in different materials, fill each with the same volume of hot water, put on lids and record the temperatures at set times.
What you should find
Matt black gives out the most infrared (so its water cools fastest) and shiny silver the least. Surfaces that are good at giving out infrared are also good at taking it in.
Stay safe
Hot water scalds and the cube gets hot. Stand it on a heatproof mat and don’t touch the sides.
Where marks go
Keep the detector at exactly the same distance from each face, or the readings can’t be compared.

Back to the list · GCSE Physics questions

06 / Picking up the marksHabits that work for every practical

Five habits examiners reward

  1. Name the instrument

    Say what you’d measure with, and what it measures: “a measuring cylinder to measure 25 cm³ of acid”, not just “measure the acid”.

  2. Say why you repeat

    Repeating only earns credit with a reason: to spot anomalous results, or to work out a mean.

  3. Give the safety reason

    A precaution needs its hazard: “wear eye protection because the acid is an irritant”, not just “be careful”.

  4. Never write “human error”

    It never scores. Say exactly what went wrong, such as judging when the cross disappears.

  5. Describe the pattern

    Say which way it goes and its shape: “as the length doubles, the resistance doubles”.

Test yourself: biology practicals

Questions from the app’s required practicals topic, with the answer and the reason.

01 / Required practicalsBoth tiers

Put these steps for focusing a light microscope in order.

  1. ARefocus using only the fine focus
  2. BUse the fine focus to make the image sharp
  3. CClip the slide on the stage, with the lowest-power objective in place
  4. DUse the coarse focus to get the cells roughly clear
  5. ESwap to a higher-power objective lens
Show the answer

The right order: C, D, B, E, A

  1. Clip the slide on the stage, with the lowest-power objective in place
  2. Use the coarse focus to get the cells roughly clear
  3. Use the fine focus to make the image sharp
  4. Swap to a higher-power objective lens
  5. Refocus using only the fine focus

Start on the lowest power, where the field of view is widest, so the cells are easy to find. Coarse focus gets them roughly clear and fine focus sharpens them. Only then move up to a higher power.

Checked against OpenStax Biology 2e, 4.1 Studying Cells

02 / Required practicalsBoth tiers · separate only

What does a large clear zone around a disc show?

  1. AThe bacteria are resistant to the substance
  2. BThe substance has evaporated
  3. CThe substance is good at stopping bacteria growing
  4. DThe bacteria grew best there
Show the answer

Answer: C The substance is good at stopping bacteria growing

The substance spreads out from the disc into the agar. Where it stops bacteria growing, the agar stays clear. Measuring the diameter lets you work out the area of the clear zone with πr², so the substances can be compared.

Checked against AQA GCSE Biology (8461) specification, Required practical activity 2

03 / Required practicalsBoth tiers

Put these steps of the amylase and pH practical in order.

  1. AAdd a drop of the mixture to iodine at regular intervals
  2. BNote the time when the iodine stays orange-brown
  3. CWait for them to reach the bath temperature
  4. DPut the starch, amylase and buffer in a water bath
  5. EMix them and start the stopwatch
Show the answer

The right order: D, C, E, A, B

  1. Put the starch, amylase and buffer in a water bath
  2. Wait for them to reach the bath temperature
  3. Mix them and start the stopwatch
  4. Add a drop of the mixture to iodine at regular intervals
  5. Note the time when the iodine stays orange-brown

The solutions are warmed to the same temperature before mixing. Drops of the mixture are tested with iodine at set intervals, which is continuous sampling. When the iodine no longer turns blue-black, the starch has all been digested.

Checked against AQA GCSE Biology (8461) specification, Required practical activity 5

04 / Required practicalsBoth tiers

Which instrument measures light intensity at each quadrat?

  1. AA measuring cylinder
  2. BA light meter
  3. CA pH probe
  4. DA thermometer
Show the answer

Answer: B A light meter

Abiotic factors are measured with instruments, such as a light meter for light intensity. To compare two areas fairly, use the same size of quadrat and the same number of quadrats in each.

Checked against AQA GCSE Biology (8461) specification, Required practical activity 9

Test yourself: chemistry practicals

Questions from the app’s required practicals topic, with the answer and the reason.

01 / Required practicalsBoth tiers

Put the steps for making pure, dry copper sulfate crystals from copper oxide in order.

  1. ALeave the solution to cool so crystals form
  2. BAdd copper oxide, stirring, until some is left over
  3. CWarm some dilute sulfuric acid
  4. DFilter off the excess copper oxide
  5. EPat the crystals dry with filter paper
  6. FHeat the filtrate to evaporate some of the water
Show the answer

The right order: C, B, D, F, A, E

  1. Warm some dilute sulfuric acid
  2. Add copper oxide, stirring, until some is left over
  3. Filter off the excess copper oxide
  4. Heat the filtrate to evaporate some of the water
  5. Leave the solution to cool so crystals form
  6. Pat the crystals dry with filter paper

The base goes in until no more reacts, so all the acid is used up. Filtering removes the leftover solid. Some water is evaporated, then the solution cools and crystals of the salt form.

Checked against AQA GCSE Chemistry 8462 specification, 8.2.1 Required practical activity 1 (with 4.4.2.3 Soluble salts)

02 / Required practicalsBoth tiers · separate only

Why is the burette rinsed with the acid before it is filled?

  1. ASo the scale is easier to read
  2. BSo leftover water does not dilute it
  3. CSo the burette warms up
  4. DSo the acid reacts faster
Show the answer

Answer: B So leftover water does not dilute it

Water left in the burette would dilute the acid, so more would be needed. Water in the conical flask does not matter: the pipette still delivers the same amount of alkali, and that is what the acid neutralises.

Checked against AQA GCSE Chemistry 8462 specification, 4.4.2.5 Titrations and Required practical 2

03 / Required practicalsBoth tiers

On a graph of gas volume against time, why does the line level off?

  1. AThe reaction has sped up
  2. BThe gas syringe has broken
  3. COne reactant has been used up
  4. DThe catalyst has run out
Show the answer

Answer: C One reactant has been used up

The gradient of the line shows the rate. It is steepest at the start, when the reactants are most concentrated. As they are used up it gets less steep, and it is flat once one reactant has run out.

Checked against AQA GCSE Chemistry 8462 specification, 4.6.1.1 Calculating rates of reactions

04 / Required practicalsBoth tiers · separate only

Put the steps of the test for halide ions in a solid in order.

  1. AAdd dilute nitric acid
  2. BDissolve the solid in distilled water
  3. CAdd a few drops of silver nitrate solution
  4. DNote the colour of any precipitate
Show the answer

The right order: B, A, C, D

  1. Dissolve the solid in distilled water
  2. Add dilute nitric acid
  3. Add a few drops of silver nitrate solution
  4. Note the colour of any precipitate

Tap water contains dissolved ions such as chloride, which would give their own results. The acid removes carbonate ions, which would also form a precipitate, and the colour of the silver halide precipitate shows which halide is there.

Checked against AQA GCSE Chemistry 8462 specification, 4.8.3 Identification of ions and Required practical 7

Test yourself: physics practicals

Questions from the app’s required practicals topic, with the answer and the reason.

01 / Required practicalsBoth tiers

What does the specific heat capacity practical find out about a material?

  1. AThe energy needed to warm 1 kg of it by 1 °C
  2. BThe energy needed to melt 1 kg of it
  3. CHow quickly it cools down in a cold room
  4. DThe temperature at which it starts to melt
Show the answer

Answer: A The energy needed to warm 1 kg of it by 1 °C

You supply a measured amount of energy, measure the mass and the temperature rise, and work out the energy needed per kilogram per degree. That value is the specific heat capacity, in J/kg °C.

Checked against AQA GCSE Physics 8463 specification, 8.2.1 Required practical activity 1

02 / Required practicalsBoth tiers

What do voltmeters across each branch of a parallel circuit show?

  1. AA bigger p.d. on later branches
  2. BZero p.d. across each branch
  3. CThe same p.d. across each branch
  4. DThe p.d. halves at each new branch
Show the answer

Answer: C The same p.d. across each branch

Each parallel branch is connected across the same two points, so each has the same p.d. In series the supply p.d. is shared between the components, so their p.d.s add up to the supply p.d.

Checked against Pearson Edexcel GCSE Physics 1PH0 specification, Appendix 6 core practicals 2.19 to 10.17

03 / Required practicalsBoth tiers

On a graph of force (vertical) against extension (horizontal), the gradient of the straight part gives:

  1. AThe spring constant
  2. BThe weight of the spring
  3. CThe work done
  4. DThe elastic limit
Show the answer

Answer: A The spring constant

Force = spring constant × extension, so force ÷ extension, the gradient, is the spring constant in N/m. A stiffer spring gives a steeper line.

Checked against OCR Twenty First Century Physics B J259 specification, P6.3 material under stress

04 / Required practicalsBoth tiers

Put these steps for the glass block practical in order.

  1. AMark the rays going in and coming out
  2. BShine a ray into the block at an angle
  3. CMeasure the angles from the normal
  4. DTake the block away and join the marks
  5. EDraw round the glass block on paper
Show the answer

The right order: E, B, A, D, C

  1. Draw round the glass block on paper
  2. Shine a ray into the block at an angle
  3. Mark the rays going in and coming out
  4. Take the block away and join the marks
  5. Measure the angles from the normal

Drawing round the block lets you put it back and join the ray through it. The ray box bulb runs hot, so let it cool before moving it, and work in a dimmed room with bags tucked away so nobody trips.

Checked against OCR Gateway Physics A J249 specification, P5.1 reflection and refraction (PAG P8)

07 / QuestionsAbout practicals

Required practicals, answered

What are GCSE science required practicals?

Experiments every pupil does in class, which can then be asked about in the written exams. AQA calls them required practicals, Edexcel core practicals, and OCR practical activity groups (PAGs). At least 15% of the marks in GCSE science exams are about practical work.

Do I get marks just for doing the practicals?

No. There’s no coursework mark. Your school keeps a record that you’ve done them, and the written exams ask about the methods, results and safety.

What are independent, dependent and control variables?

The independent variable is the one you change. The dependent variable is the one you measure. Control variables are the ones you keep the same, so the test is fair.

What’s the difference between accurate and precise?

An accurate result is close to the true value. Precise results are close to each other when you repeat the measurement. Results can be precise without being accurate, for example if a balance isn’t zeroed.

What’s the difference between repeatable and reproducible?

Results are repeatable if you get similar results when you do the experiment again with the same method and equipment. They are reproducible if someone else, or a different method or piece of equipment, gets similar results.

More GCSE science

GCSE BiologyGCSE ChemistryGCSE Physics6-mark questionsGCSE Science

08 / Coming to Show WorkingPracticals in the app

Practise practicals in the app

Science is on its way to Show Working, with a required practicals topic in each science: methods to put in order, variables, safety and results. It isn’t on phones yet, and we won’t give a date until it’s ready.

Science will be one payment of £9.99, covering Combined Science and Biology, Chemistry and Physics. Spotted a mistake on this page? Tell us at support@showworking.co.uk.

Doing GCSE maths too?

Maths is the subject in Show Working today, with the working shown for every answer. See the maths topics.

Coming soon to the App Store

Change one. Measure one.

Pick one practical tonight.

Cover the card, then say the variables, the method and one safety point out loud. Check, and pick another tomorrow.

Next: 6-mark questions

Many 6-mark questions ask you to describe a practical, so the two go together.

Show WorkingComing soon to the App Store