Check your understanding with Chemistry topic questions, adaptive assessments and timed MCQ practice. Choose Cambridge IGCSE, Pearson Edexcel International GCSE or OxfordAQA International GCSE before you begin.
Explain why an answer is correct using particles, bonding, observations or the balanced equation. For calculations, write the relationship first and keep units visible throughout your working.
The tool offers topic assessments, timed practice and an untimed adaptive starting-level assessment. Your report separates unanswered questions from topics you have not studied and includes feedback to guide your next revision session.
This is diagnostic practice, not a predicted exam grade. Available questions depend on your course and paper.
What can you revise?
Particles & atomic structure
Separation, electron arrangements, isotopes and periodic trends.
Bonding & structure
Relate structure to melting point, conductivity and other properties.
Equations & amounts
Balance equations and use masses, moles and reaction ratios.
Acids, metals & electrolysis
Reaction products, reactivity, salt preparation and electron transfer.
Energy, rates & organic chemistry
Energy changes, collisions, equilibrium and functional groups.
Practical reasoning
Apparatus, measurements, observations, planning and evaluation.
Original practice examples
Try it. Then check your reasoning.
Work through these questions first. Open each explanation when you are ready to check.
Atomic structure
A sodium atom has mass number 23 and atomic number 11. How many neutrons does it contain?
Show answer and worked explanation
12 neutrons
Atomic number gives the number of protons: 11.
Mass number is the total number of protons and neutrons.
Neutrons = 23 − 11 = 12.
Revision tip: Mass number counts particles in the nucleus; it does not count electrons.
Balancing equations
Balance the equation Mg + O₂ → MgO.
Show answer and worked explanation
2Mg + O₂ → 2MgO
O₂ has two oxygen atoms, so place 2 before MgO.
There are now two magnesium atoms on the right, so place 2 before Mg.
Check both sides: two magnesium atoms and two oxygen atoms.
Revision tip: Change the coefficients in front of formulae, keeping the formulae themselves unchanged.
Amounts of substance
Calculate the amount in moles in 12.0 g of magnesium. Use a molar mass of 24.0 g mol⁻¹.
Show answer and worked explanation
0.500 mol
Use amount = mass ÷ molar mass.
Substitute: n = 12.0 ÷ 24.0.
The amount is 0.500 mol, to three significant figures.
Revision tip: Use consistent mass units and include mol in your final answer.
A revision routine you can repeat.
Choose a topic you have covered at school. Attempt questions before rereading your notes to find what you can recall independently.
Use feedback to identify the missing explanation or calculation step. Make a short correction using the relevant scientific terms.
Revisit the correction after a gap. Mix calculations, explanations and practical reasoning as your understanding improves.
Choose the right course before you start.
Which Chemistry exam boards are supported?
Choose Cambridge IGCSE Chemistry (0620), Pearson Edexcel International GCSE Chemistry (4CH1) or OxfordAQA International GCSE Chemistry (9202). Select the paper and course route available in setup.
Can I practise Cambridge Core and Extended content?
Yes. Cambridge Papers 1 and 3 use Core selections, while Papers 2 and 4 use Extended selections. Papers 5 and 6 practise experimental reasoning. The tool does not assess hands-on laboratory performance.
Are these complete official Chemistry papers?
The assessment uses multiple-choice practice and diagnostic adaptations. Use it alongside your school work and official examination resources. Topic availability varies with your board and paper.
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