Your Guide to Science Required Practicals
A clear breakdown of the practicals you need to know for AQA and Edexcel GCSE Biology, Chemistry, and Physics.
Required practicals aren't a separate exam — they're examined inside your normal papers, and they're worth a significant share of the marks. The questions are predictable once you know what examiners ask about.
What examiners actually ask
- Name the apparatus and why that piece was chosen.
- Identify the independent, dependent and control variables.
- Explain a step: why repeat readings, why a water bath, why in the dark.
- Spot the error in a given method and suggest an improvement.
- Process the results: a table, a graph, a mean, a rate from a gradient.
Biology
Microscopy and drawing cells, osmosis in potato, food tests, enzymes and pH, photosynthesis rate, reaction time, sampling and quadrats, and culturing microorganisms for AQA. Learn the safety and control points for each — they're common 2-mark answers.
Chemistry
Making a soluble salt, titration, electrolysis, temperature change in reactions, rates of reaction (both the gas-volume and the disappearing-cross methods), chromatography, and water purification. Know why each measurement is taken the way it is.
Physics
Specific heat capacity, thermal insulation for AQA, resistance of a wire, I–V characteristics, density, force and extension, acceleration, waves in a ripple tank and on a string, and light — reflection, refraction and infrared emission.
The mistakes that cost marks
- Vague variables: "the temperature" instead of "the temperature of the water, kept at 25 °C".
- Naming a precaution without a reason.
- Misreading a scale, or plotting points without checking the axes.
- Conclusions that go beyond the data collected.
How to revise them
For each practical, write one side from memory: method in numbered steps, apparatus, variables, one risk, one improvement. Then answer past-paper practical questions on it and compare with the mark scheme wording.