# How to Study Physics-Chemistry: Key Exercise Types
Physics and chemistry are not subjects you "understand" first and then "do exercises" on. It's the other way around. Without regular active practice, understanding disappears. You can follow a lesson perfectly on a Tuesday and be unable to solve a single exercise from it by Friday. This isn't an intelligence problem — it's how memory normally works. The solution is systematic: practise first, understand through practice, and space that practice across time.
Physics and chemistry are two subjects students tend to treat like history or geography — memorising definitions and formulas. This approach fails because these subjects don't test rote memory. They test the ability to mobilise knowledge in new situations, under time pressure. The only training that prepares you for this is regular practice with varied exercises.
This guide covers the 6 exercise types every student must master for A-level exams, the research-backed methods for memorising formulas and reactions, and a 6-week revision plan to structure your preparation.
The 6 Key Exercise Types at A-Level
1. Kinematics and mechanics
Mechanics exercises test command of the fundamental laws of motion — Newton's second law, energy theorems, conservation of momentum. In kinematics, the focus is on uniformly accelerated motion, free fall and projectile motion.
This type of exercise is one of the most penalising for students who haven't practised enough: sign errors, wrong axis conventions and confusion between velocity and acceleration are systematic among students who review their notes without working through problems.
Priority training: setting up reference frames and axes, resolving forces, applying Newton's second law in vector form, deriving trajectory equations.
2. Optics
Optics exercises cover refraction (Snell's law), image formation in converging and diverging lenses, and dispersion. These exercises combine geometric constructions and algebraic calculations — students who only practise one of the two aspects arrive at the exam unable to handle the other.
Priority training: geometric constructions of images, applying the thin lens equation, calculating magnification, Gaussian optics conditions.
3. Organic chemistry
Organic chemistry exercises test recognition of functional groups, reaction mechanisms and nomenclature. Unlike other exercise types, organic chemistry requires heavy memorisation — families of compounds, reagents, products, reaction conditions — which can't be acquired without active repetition.
Priority training: identifying functional groups, substitution/addition/elimination reactions, writing structural and semi-structural formulas, multi-step synthesis problems.
4. Acids and bases
Acid-base exercises draw on pH, Ka, acid dissociation constants and chemical equilibrium. The most frequent error is confusing the strength of an acid with its concentration — two distinct concepts that students mix up through lack of practice with varied exercises.
Priority training: pH calculations for strong and weak acids, identifying conjugate acid-base pairs, neutralisation reactions, interpretation of pH-volume titration curves.
5. Electricity
Circuit exercises test Kirchhoff's laws, properties of components (resistors, capacitors, inductors) and RC and RL transient behaviour. These exercises are often well-handled by students who have practised regularly — and disastrous for those who learned the laws without applying them in context.
Priority training: mesh and node laws, steady-state circuit analysis, capacitor charge and discharge curves, applying Ohm's law across a full circuit.
6. Nuclear transformations
Radioactivity and nuclear reactions are a type of exercise students frequently underestimate — the calculations are relatively accessible but conceptual errors (confusing fission and fusion, misapplying conservation laws) cost marks on questions that should be straightforward.
Priority training: conservation of mass number and atomic number, writing decay equations, calculating energy released in nuclear reactions, half-life calculations.
Memorising Physics Formulas with Flashcards
Why flashcards work
Karpicke and Roediger (2006) showed in a landmark study that forcing yourself to retrieve information from memory — without looking at it — strengthens the memory trace far more than re-reading the same information. This phenomenon, called the testing effect, is one of the most robust findings in cognitive psychology research on learning (Karpicke & Roediger, 2006).
Applied to physics formulas, the principle is direct: you don't learn a formula by re-reading it in your notes. You learn it by trying to write it from memory, checking whether you were right, and repeating this process at increasing intervals.
Dunlosky et al. (2013) ranked the most effective learning techniques in a meta-analysis covering dozens of studies. Practice testing and distributed practice consistently appear at the top — well above highlighting or re-reading, which students use most often (Dunlosky et al., 2013).
How to create an effective physics flashcard
An effective physics flashcard is not a "formula → numerical value" card. It needs three layers:
Front (question): What is Newton's second law of motion?
Back (three-layer answer): - Formula: F = ma (vector form: the net force equals mass times acceleration) - Units: F in newtons (N), m in kilograms (kg), a in m/s² - Conditions of application: inertial reference frame, constant mass, classical (non-relativistic) mechanics
This three-layer structure forces you to check that you know not only the formula, but that you could apply it correctly in an exercise — including verifying dimensional consistency and identifying conditions of use.
Create one card per formula, per law, and per key definition. For A-level physics and chemistry, this represents roughly 80 to 120 cards. This may sound like a lot, but with spaced repetition, each card takes only seconds per session once mastered.
Wizidoo lets you create these flashcards directly from your notes or your official formula sheet, and automatically generates adaptive quizzes that track what you already know and what you tend to forget. For a deeper understanding of how spaced repetition works, see our guide on spaced repetition and long-term memory. Create your flashcards for free.
The 5-Step Method for Solving a Physics Exercise
One of the most costly mistakes in physics is starting to write formulas before analysing the problem. This rushing produces incorrect solutions even when the student knows the relevant laws. Here is the 5-step method that prevents this error.
Step 1: read the whole problem before writing anything
Read the entire problem before putting pen to paper. Mentally note the given quantities, the quantities you're asked to find, and the physical context. This full read takes 90 seconds and prevents tens of minutes of wasted work.
Step 2: identify the type of problem and the applicable laws
From the given quantities and the physical situation, identify the type of problem among the categories you know: mechanics, optics, electricity, etc. Each type has its reference laws. This identification directs the entire solution.
Step 3: write the equations before calculating
Write equations in literal (symbolic) form before substituting numerical values. This step lets you verify dimensional homogeneity, catch reasoning errors before they compound, and earn partial credit if the final answer is incorrect.
Step 4: solve and express the result with correct units
Perform the numerical calculation and express the result with the correct units. If the result is a vector, specify its direction and sense. If the problem asks for an order of magnitude, check that your result is physically plausible.
Step 5: verify homogeneity and physical consistency
Before moving to the next question, check two things: dimensional homogeneity (that the units of your result match the quantity you were asked to find) and physical consistency (a car speed of 10,000 m/s should raise an alarm, even if the calculation seemed correct). This check takes one minute and catches errors that calculation alone doesn't reveal.
Chemistry: Memorising Reactions and Balancing Equations
Why re-reading doesn't work
In chemistry, memorising reactions through re-reading is particularly ineffective. The brain confuses reactants and products, forgets reaction conditions, and loses stoichiometric coefficients. The reason is well-documented: memory encodes actively retrieved information far better than passively read information — again, the testing effect.
The correct method for memorising a chemical reaction is not to read it ten times. It's to ask yourself "what are the reactants and products of this reaction?" without looking at your notes, verify your answer, and then return to this question after an interval.
How to create an active quiz for chemistry
For each reaction you need to master, build a card (or quiz question) with the following structure:
Question: What are the products of the base hydrolysis of an ester? Answer: A carboxylate salt and an alcohol (saponification — alkaline conditions, complete reaction).
Question: What are the reaction conditions for esterification? Answer: Concentrated sulfuric acid catalyst, heat, slow and reversible equilibrium (yield below 100% without a forcing procedure).
For equation balancing, practice must be active and repeated. Bjork (2011) showed that "desirable difficulties" — errors, blocks, failed attempts followed by correction — produce more durable learning than easy exercises. Balancing equations without help, even incorrectly, is better than copying balanced equations.
Practical rule: balance atoms other than hydrogen and oxygen first, then oxygen, then hydrogen. Always check charge conservation for ionic equations.
Past Papers: The Most Under-Exploited Resource
How many years of past papers to use
Four years minimum. A single past paper doesn't let you identify structural themes. Four years is enough to distinguish what comes up systematically (nuclear transformations, mechanics, acid-base titrations) from what appears rarely.
How to sort by exercise type
Don't work through past papers in chronological order. Sort exercises by topic first: collect all mechanics exercises from four years, then all optics exercises, and so on. This sorting quickly reveals recurring formats, habitual traps and the expected difficulty level for each type.
How to work through a past paper effectively
The rule is simple: complete the exercise fully without consulting the mark scheme. If you get stuck on a question, note the point of difficulty and move on. Once finished, compare with the mark scheme and identify precisely the steps where your reasoning diverged.
This method is uncomfortable — and that's exactly its advantage. Bjork (2011) showed that difficulty felt during practice, far from being a negative signal, is often a sign that learning is taking place. Students who find past papers difficult because they attempt them without looking at corrections in advance progress more than those who find them easy because they consulted answers first. For strategies on overcoming conceptual blocks in science, our guide on unblocking maths difficulties covers principles that apply equally to physics.
A 6-Week Revision Plan for Physics and Chemistry
General principle
Alternate physics and chemistry chapters to avoid saturation. Progress from simpler to more complex within each domain. Reserve the final two weeks for past papers and targeted revision.
Week 1 — Physics fundamentals
Kinematics and mechanics. Active revision of laws (flashcards), 3 exercises per day. Goal: write the equations without help for 80% of situations encountered.
Week 2 — Chemistry fundamentals
Acids and bases, plus organic chemistry (functional groups and nomenclature). Create reaction flashcards. 20 minutes of active daily quizzing on reactions to memorise.
Week 3 — Secondary physics topics
Optics and electricity. Same method: flashcards, exercises without consulting the mark scheme immediately, identification of recurring errors.
Week 4 — Secondary chemistry topics
Nuclear transformations, advanced organic chemistry (multi-step synthesis, mechanisms). First contact with past papers: select 4 exercises from topics already covered and do them under semi-real conditions.
Week 5 — Full past papers
One complete past paper per day under real conditions (timed, no access to notes). Mark it in the evening: list of points to revise. Spaced repetition on flashcards in progress.
Week 6 — Consolidation
Targeted revision of gaps identified in week 5. Two additional past papers. No new content. Light review of the most important formulas the day before the exam.
FAQ
Is physics-chemistry about understanding or memorising?
Both, in a specific order. Understanding comes first — if you apply a formula without knowing what it represents physically, you'll be stuck the moment an exercise moves away from the standard case. But understanding without memorisation isn't enough either: in an exam under time pressure, you can't reconstruct a formula from scratch. Memorisation makes understanding immediately deployable. Both are necessary, and active practice through exercises is what installs both simultaneously.
How many hours per week should I spend on physics and chemistry?
For an A-level student aiming for high grades, 6 to 8 hours per week outside of lessons is a reasonable volume during the 6 weeks before exams. Outside this period, 3 to 4 hours per week is enough to maintain what you've learned. Distribution matters more than raw volume: 5 sessions of 60 to 90 minutes are more effective than one 8-hour session at the weekend.
What if I'm lost and have been since the start of the year?
Don't try to catch up on everything at once. Start by identifying the fundamental prerequisites you haven't mastered — in physics, Newton's laws and basic energy concepts; in chemistry, chemical equilibrium and acid-base reactions. These fundamentals determine whether you can understand everything else. Work on these priority areas with progressively levelled exercises, then move back up to the full A-level syllabus. A complete catch-up in 6 weeks is possible, but only with daily structured practice through exercises — not through re-reading notes.
References
- Bjork, R. A. (2011). On the symbiosis of remembering, forgetting, and learning. In A. S. Benjamin (Ed.), Successful remembering and successful forgetting: A festschrift in honor of Robert A. Bjork (pp. 1-22). Psychology Press.
- Dunlosky, J., Rawson, K. A., Marsh, E. J., Nathan, M. J., & Willingham, D. T. (2013). Improving students' learning with effective learning techniques: Promising directions from cognitive and educational psychology. Psychological Science in the Public Interest, 14(1), 4-58. https://doi.org/10.1177/1529100612453266
- Karpicke, J. D., & Roediger, H. L. (2006). Test-enhanced learning: Taking memory tests improves long-term retention. Psychological Science, 17(3), 249-255. https://doi.org/10.1111/j.1467-9280.2006.01693.x
- Karpicke, J. D., & Roediger, H. L. (2008). The critical importance of retrieval for learning. Science, 319(5865), 966-968. https://doi.org/10.1126/science.1152408