Periodicity of chemical properties of the elements in Period 3: past paper questions

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• Question 17May/June 2026, paper 11Multiple choice1 markHas a diagram

  The table contains some statements about Period 3 elements and their compounds. In which row are both statements correct?

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• Question 17Oct/Nov 2025, paper 11Multiple choice1 mark

  Three equations are listed. $x$, $y$ and $z$ are all whole numbers.

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• Question 16Oct/Nov 2024, paper 11Multiple choice1 markHas a diagram

  What are the acid–base nature and structure of ${\text{SO}}_2$?

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• Question 16Oct/Nov 2023, paper 11Multiple choice1 mark

  X, Y and Z are elements all found within Groups 13, 14 and 15 of the Periodic Table. X is in the same group in the Periodic Table as Y. Y and Z are in Period 3.

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• Question 16May/June 2026, paper 12Multiple choice1 mark

  Which statement about the Period 3 elements sodium to phosphorus and their compounds is correct?

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• Question 18Oct/Nov 2025, paper 11Multiple choice1 mark

  Which oxide has a simple structure rather than a giant structure?

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• Question 17Oct/Nov 2024, paper 11Multiple choice1 markHas a diagram

  Elements X and Y are in Period 3 of the Periodic Table. Element X is either phosphorus or sulfur. Element Y is either sodium or magnesium.

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• Question 18Oct/Nov 2023, paper 11Multiple choice1 markHas a diagram

  Bromocresol green is an acid-base indicator. Below a pH of 3.8 it is yellow. Above a pH of 5.4 it is blue.

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• Question 19May/June 2026, paper 12Multiple choice1 mark

  The chloride of element J is added to a beaker of water. The oxide of element J is then added to the same beaker.

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• Question 18Oct/Nov 2025, paper 12Multiple choice1 mark

  Compound $\text{X}$ is an oxide of a Period 3 element. Compound $\text{X}$ is a white solid at $25{}^{\circ }\text{C}$. It reacts with water to form an acidic solution.

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• Question 18Oct/Nov 2024, paper 11Multiple choice1 mark

  Q is a semi-conductor. The chloride of Q reacts with water to form white fumes and an acidic solution. Which Period 3 element is Q?

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• Question 20Oct/Nov 2023, paper 12Multiple choice1 mark

  Four mixtures are added to four separate $50{\text{ cm}}^3$ samples of water and stirred. Which mixture results in a solution with the highest pH?

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• Question 16May/June 2026, paper 13Multiple choice1 mark

  Elements W, X, Y and Z are different elements in Period 3 of the Periodic Table. Four statements about W, X, Y and Z are given. 1 X has the greatest electronegativity value of the four elements.

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• Question 23Oct/Nov 2025, paper 12Multiple choice1 mark

  Element $\text{E}$ is in Period 3. It forms a chloride which reacts with a small amount of water to produce a white precipitate and steamy fumes. This precipitate is soluble in $\text{NaOH(aq)}$ and in $\text{HCl(aq)}$.

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• Question 17Oct/Nov 2024, paper 12Multiple choice1 mark

  Which oxide is insoluble in aqueous sodium hydroxide?

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• Question 5Oct/Nov 2023, paper 13Multiple choice1 markHas a diagram

  Solid aluminium chloride sublimes at $178{}^{\circ }\text{C}$. Which structure best represents the species in the vapour at this temperature?

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• Question 1May/June 2026, paper 22Structured14 marks

  Oxygen reacts with many elements. State the total number of electrons that occupy the 2p sub-shell in an oxygen atom.

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• Question 18Oct/Nov 2024, paper 12Multiple choice1 markHas a diagram

  Sodium and sulfur are burned separately in oxygen. Each reaction has a distinctive coloured flame. Which row is correct?

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• Question 1May/June 2026, paper 23Structured12 marks

  The chlorides of Period 3 elements show different physical and chemical properties.

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• Question 2Oct/Nov 2025, paper 21Structured11 marksHas a diagram

  The Period 3 elements show trends in physical and chemical properties across the period.

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• Question 1Oct/Nov 2023, paper 22Structured13 marks

  The elements silicon, phosphorus and sulfur are in Period 3 of the Periodic Table. Describe the variation in atomic radius from silicon to sulfur.

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• Question 18May/June 2023, paper 11Multiple choice1 markHas a diagram

  $\mathrm{S}\mathrm{i}{\mathrm{O}}_2$ has a melting point of $1713{}^{\circ }\mathrm{C}$. It reacts with hot $\mathrm{N}\mathrm{a}\mathrm{O}\mathrm{H}(\mathrm{a}\mathrm{q})$ to form sodium silicate, $\mathrm{N}{\mathrm{a}}_2\mathrm{S}\mathrm{i}{\mathrm{O}}_3$, and water. No reaction occurs when $\mathrm{S}\mathrm{i}{\mathrm{O}}_2$ is added to hot ${\mathrm{H}}_2\mathrm{S}{\mathrm{O}}_4(\mathrm{a}\mathrm{q})$.

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• Question 24May/June 2025, paper 11Multiple choice1 markHas a diagram

  Compound X contains two Period 3 elements, Y and Z. Compound X reacts with water to form only two products: a slightly soluble hydroxide and compound Q. Q is a compound of element Z and hydrogen. Compound Q burns in moist air to produce an oxide and water.

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• Question 2Oct/Nov 2024, paper 22Structured15 marksHas a diagram

  Oxygen is a Group 16 element. Write equations for the following reactions.

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• Question 19May/June 2023, paper 11Multiple choice1 mark

  Element X has the second largest atomic radius in its period. An atom of X has three occupied electron shells only. The oxide of X is shaken with water.

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• Question 16May/June 2025, paper 12Multiple choice1 mark

  The oxide and chloride of an element X are separately mixed with water. The two resulting solutions have the same effect on litmus. What could element X be?

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• Question 3Oct/Nov 2024, paper 23Structured20 marksHas a diagram

  The Group 14 elements show a change from non-metallic to metallic character down the group.

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• Question 18May/June 2023, paper 12Multiple choice1 mark

  In reactions 1 and 2, X represents an element in Period 3. In each reaction, X is forming a product where X is in its highest oxidation state.

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• Question 18May/June 2025, paper 12Multiple choice1 markHas a diagram

  Compound M is a white solid. It is the chloride of a Period 3 element. Information about some reactions starting with compound M is given in the table.

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• Question 16May/June 2024, paper 11Multiple choice1 mark

  Elements Y and Z are both in Period 3 of the Periodic Table. When the chloride of element Y is added to water, it reacts and a solution of $\text{pH }2$ is produced. When the chloride of element Z is added to water, it dissolves and a solution of $\text{pH }7$ is produced.

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