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Pearson Edexcel · GCSE · Chemistry
1 Key concepts in chemistry Topical Past Papers
Pearson Edexcel GCSE Chemistry past-paper questions on "Key concepts in chemistry" grouped from the official 2026 Edexcel specification. Free to browse.
Pearson Edexcel GCSE Chemistry topical past papers — Topic: Key concepts in chemistry — free, no signup. Original Chemistry past papers and mark schemes from the official source, compiled for you. This free archive covers 53 past-paper components — questions grouped by topic, mark scheme alongside, no worked solutions. Free to browse online — no signup, no download limits.
What's in your Topic: Key concepts in chemistry
Edexcel GCSE Chemistry topical past papers for the scope you picked — Topic: Key concepts in chemistry. Every past-paper question is reproduced with the original wording and paired with the official mark scheme — questions only, no worked solutions on this free archive.
Questions are organised so you can revise systematically without opening a dozen separate session PDFs. If you want step-by-step worked solutions to the same questions, the Topical Solved version is one click away.
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Always current, always free
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Chemistry topical past papers — what students search for
Students search for "Chemistry topical past papers", "Chemistry topic-wise questions", "Chemistry chapter-wise past papers", "Chemistry questions by topic", "free Edexcel Chemistry past papers by topic", and dozens more variations every day. This free page is the canonical landing spot for every topic-wise variant of Chemistry — open the topic you need and the questions are right there.
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Subtopics within Key concepts in chemistry
Describe how the Dalton model of an atom has changed over
Describe the structure of an atom as a nucleus containing
Recall the relative charge and relative mass of:
Explain why atoms contain equal numbers of protons and
Describe the nucleus of an atom as very small compared to the
Recall that most of the mass of an atom is concentrated in the
Recall the meaning of the term mass number of an atom
Describe atoms of a given element as having the same number
Describe isotopes as different atoms of the same element
Calculate the numbers of protons, neutrons and electrons in
Explain how the existence of isotopes results in relative atomic
Calculate the relative atomic mass of an element from
Describe how Dmitri Mendeleev arranged the elements, known
Describe how Dmitri Mendeleev used his table to predict the
Explain that Dmitri Mendeleev thought he had arranged
Explain the meaning of atomic number of an element in terms
Describe that in the periodic table
Identify elements as metals or non-metals according to their
Predict the electronic configurations of the first 20 elements in
Explain how the electronic configuration of an element is related
Explain how ionic bonds are formed by the transfer of electrons
Recall that an ion is an atom or group of atoms with a positive
Calculate the numbers of protons, neutrons and electrons in
Explain the formation of ions in ionic compounds from their
Explain the use of the endings –ide and –ate in the names of
Deduce the formulae of ionic compounds (including oxides
Explain the structure of an ionic compound as a lattice structure
Explain how a covalent bond is formed when a pair of electrons
Recall that covalent bonding results in the formation of
Recall the typical size (order of magnitude) of atoms and small
Explain the formation of simple molecular, covalent substances
Explain why elements and compounds can be classified as:
Explain the properties of ionic compounds limited to:
Explain the properties of typical covalent, simple molecular
Recall that graphite and diamond are different forms of carbon
Describe the structures of graphite and diamond
Explain, in terms of structure and bonding, why graphite is used
Explain the properties of fullerenes including C60 and graphene
Describe, using poly(ethene) as the example, that simple
Explain the properties of metals, including malleability and the
Describe the limitations of particular representations and
Describe most metals as shiny solids which have high melting
Calculate:
Calculate the formulae of simple compounds from reacting
Deduce:
Describe an experiment to determine the empirical formula of a
Explain the law of conservation of mass applied to:
Calculate masses of reactants and products from balanced
Calculate the concentration of solutions in g dm–3
Recall that one mole of particles of a substance is defined
Calculate the number of:
Explain why, in a reaction, the mass of product formed is
Deduce the stoichiometry of a reaction from the masses
Frequently Asked Questions
Is this Chemistry topical archive really free?
Yes. Every Edexcel Chemistry past-paper question grouped by topic on this page is free to browse online — no signup, no paywall, no download limit. The only paid option is Topical Solved, which adds a step-by-step worked solution to each question.
What's the difference between this and Topical Solved?
This free archive gives you the questions grouped by topic with the official mark scheme alongside — questions only. Topical Solved is the same questions plus a teacher-verified, step-by-step worked solution for each one, so you can see exactly how the marks are earned.
Is the mark scheme included?
Yes — every question is shown next to its official mark scheme, so you can attempt it and mark your own answer without leaving the page.
How up to date is the Chemistry archive?
As soon as Edexcel releases a new Chemistry session, the new questions are filed under the right syllabus topic here — so the archive already includes the freshest session the day after results day, still free.