Edexcel A-Level Physics core practicals: A complete guide

The thing that causes the most stress every year, and it's worth clearing up before anything else: the Science Practical Endorsement does not affect your A-Level grade. It sits on your certificate as a separate line, Pass or Not Classified, judged by your teachers across the two years of the course against something called CPAC (the Common Practical Assessment Criteria). Your grade comes from Papers 1, 2 and 3 alone. If your Endorsement comes out as a fail, your A-Level grade is unchanged. If it comes out as a pass, your grade is still unchanged. They're reported next to each other, not stacked on top of each other.

It matters because a lot of students revise thinking the Endorsement is some hidden slice of the mark that'll quietly drag them up or down. It isn't. Universities can see it, and a few physics or engineering degrees want to see a pass, but the grade and the Endorsement are two separate judgements that happen to turn up on the same bit of paper.

On to the actual content. Edexcel A-Level Physics (9PH0) has 16 core practicals running across the two years. They cover a bit of everything: mechanics, materials, waves, electricity, oscillations, thermodynamics, nuclear physics. They get tested in two places, which keeps catching people out. First, through written questions on Papers 1, 2 and 3 (Paper 3 is where most of it lives, since it's the synoptic one). Second, through the teacher-assessed Endorsement that doesn't count toward your grade. This guide walks through all 16, explains both teaching routes, and shows where the practical-skills marks actually live in the written papers.

These are the official Edexcel titles, lifted straight from the 9PH0 specification. One thing to know up front: there are two teaching routes to the same qualification. The concept-led route is the standard one most schools run. The context-led route, called Salters Horners Advanced Physics (SHAP), teaches the same content through real-world contexts like medical imaging or transport. Same 16 practicals, same three papers, same grade at the end. Only the order and the framing differ. If your course does practicals in a weird order compared to the list below, you're probably on SHAP.

Edexcel assesses practical work in two parallel ways. The written exams carry the grade. The Endorsement sits alongside and gets its own line on the certificate.

Paper 3 is the synoptic one, and it's where most of what Edexcel calls "indirect practical skills" questions live. The wording in the spec itself is that Paper 3 will include questions assessing conceptual and theoretical understanding of experimental methods, drawing on students' experiences of the core practicals. Which is a long way of saying: they'll give you a method and ask you to pick it apart.

Papers 1 and 2 carry practical-skills questions too, usually tied to whatever topic is being tested. Graph analysis, uncertainty calculations, method evaluation. These turn up across all three papers, so don't assume they're a Paper 3 thing only.

One figure worth knowing: at least 40% of the marks across the three papers are given for maths at Level 2 or above. That's the highest maths weighting of any Edexcel A-Level science. Uncertainty calculations and graph work eat up a chunk of that.

Of all the A-Level sciences, physics leans hardest on uncertainty as a numerical thing you actually calculate rather than wave your hands at. You're expected to work out absolute and percentage uncertainty from a single reading. For a 1 mm ruler that's ±0.5 mm, so percentage uncertainty is (0.5 / measurement) × 100.

You also need to combine uncertainties when you combine measurements. For multiplying or dividing, percentage uncertainties add. For adding or subtracting, absolute uncertainties add. For powers, the percentage uncertainty scales by the exponent. And you need to spot which uncertainty is dominating: if one measurement has 15% uncertainty and another has 1%, the first one is doing all the work and the second one barely matters.

On top of that there's graph work: plotting data with error bars, drawing best-fit and worst-fit lines, reading off a gradient with its uncertainty attached. Students who drill this from Year 12 onwards tend to score noticeably higher on Paper 3 than students who try to pick it up in April of Year 13.

A quick note on names, because this one trips up students who've switched boards between GCSE and A-Level.

Edexcel calls them core practicals. AQA calls them required practicals. OCR calls them Practical Activity Groups, or PAGs. CIE doesn't publish a numbered list of experiments at all. And the practicals themselves aren't the same across boards. Edexcel's falling-ball viscosity practical isn't on AQA's list. OCR's PAGs group skills together rather than listing specific experiments. If you did GCSE AQA Physics and you're now doing A-Level Edexcel, don't assume anything carries over. Start from the Edexcel list above and work from there.

For the Endorsement bit, your teacher is judging you against five strands collectively known as CPAC (the Common Practical Assessment Criteria). You need to show competence against each of them across the two years, not against every one on every practical.

A minimum of 12 practical activities is needed to support the Endorsement. Doing all 16 clears that comfortably. Pearson sends out monitoring visits, coordinated across boards by JCQ, to check that teachers' Pass/Not Classified judgements line up with national standards.

Across the three papers (but Paper 3 most of all), practical questions come in a handful of recognisable shapes.

There's the evaluate-a-method one: you spot a weakness in the method they've given you, and you suggest something specific that fixes it. "Use a digital micrometer reading to 0.01 mm instead of a 1 mm ruler, reducing the uncertainty from ±0.5 mm to ±0.005 mm" gets you the marks. "Use a more accurate ruler" doesn't.

There's the uncertainty one: calculate it as a percentage or an absolute value, from a set of readings or off a graph, and work out which source is dominating.

There's the graph one: read a gradient or intercept, work out what physical quantity it actually represents, give the answer with units and sensible significant figures.

There's the variables one: name the independent, dependent and controlled variables, and say how you'd keep each control variable constant. The key is specificity. Not "keep the temperature the same" but "use a thermostatically controlled water bath at 25.0 °C ±0.2 °C".

And there's the safety one: name a specific hazard, pair it with a specific precaution. For Practical 15, the hazard is ionising radiation and the precautions are things like handling the source with tongs, keeping maximum distance when it's not being used, and storing it in lead-lined storage. Not just "wear goggles".

A handful of mistakes come up on examiner reports year after year. Each one is preventable with past-paper practice.

False precision in tables. If you measured with a 1 mm ruler, record 24.3 cm or 243 mm, not 24.30 cm. The decimal places you write have to match the resolution of the apparatus you used. Students lose a mark here and a mark there and it adds up fast.

Confusing random and systematic errors. Repeating readings fixes random error, not systematic error. A wrongly calibrated balance will give you consistent wrong readings no matter how many times you repeat.

Vague improvements. The marker wants a named piece of apparatus, a named improvement, and a link back to the weakness you identified. "Use better equipment" is a wasted line.

Missing units on calculated answers. 9.8 isn't an answer for g; 9.8 m s^–2 is. Markers are strict about this at A-Level.

Ignoring the error-bar question. If the question gives you data with error bars and asks for the gradient's uncertainty, you need to draw a worst-fit line and compare its gradient to your best-fit one. Students who skip the worst-fit step pick up the gradient marks but drop the uncertainty marks sitting right next to them.

You can't revise this paper by reading methods back to yourself. Practical questions test skills, and skills come from doing things.

For each of the 16 core practicals, write out from memory: aim, apparatus, method in bullet points, expected results, the key graph, the typical calculation. Then compare what you wrote to your lab notebook or textbook. The gaps are what you don't actually know.

Work through past Paper 3 practical questions. Edexcel's assessment materials go back to 2017, so there's plenty to get through. After every question, read the examiner's report. That's where the specific marking criteria are described in detail, and it's probably the most undervalued revision resource for this paper. Students who read examiner reports after every past paper tend to catch patterns that teachers haven't explicitly flagged in lessons.

Drill uncertainty calculations until they're automatic. Percentage uncertainty from a single reading, combined uncertainty across a calculation, dominant uncertainty, worst-fit gradients. These come up on nearly every Paper 3.

Practise plotting graphs by hand, not in a spreadsheet. The exam expects a ruled best-fit line, error bars where they've given you them, a gradient calculated from two well-separated points on the line, and units on everything.

Our A-Level Physics course on Cognito covers the full 9PH0 syllabus including worked examples of all 16 core practicals and detailed walkthroughs of Paper 3 practical-skills questions. For broader revision strategy, our A-Level revision techniques guide covers active recall and spaced practice.