AQA GCSE Chemistry — Paper 1 (Foundation Tier)

Total marks: 100 · Duration: 105 minutes · Tier: Foundation

Instructions to candidates

• Answer all questions in the spaces provided.
• You are expected to use a calculator where appropriate.
• This paper covers Topics 1–5: Atomic Structure and the Periodic Table, Bonding, Structure and Properties, Quantitative Chemistry, Chemical Changes, and Energy Changes.
• A periodic table is provided.
• The maximum mark for this paper is 100. The marks for each question are shown in brackets.

Paper

Section A — Multiple Choice (10 marks)

For each question, choose the one correct answer.

1. What is the relative charge of an electron? (1 mark) A) +1 B) 0 C) −1 D) +2

2. Most of the mass of an atom is in its… (1 mark) A) electrons B) nucleus C) shells D) surface

3. Group 1 elements are also known as the… (1 mark) A) halogens B) noble gases C) alkali metals D) transition metals

4. A substance with a giant ionic structure will… (1 mark) A) have a low melting point B) conduct when molten C) be a gas at room temperature D) never dissolve

5. The relative formula mass of water (H₂O) is (Ar: H = 1, O = 16)… (1 mark) A) 17 B) 18 C) 16 D) 2

6. What is formed when an acid reacts with an alkali? (1 mark) A) A salt and hydrogen B) A salt and water C) Hydrogen only D) Carbon dioxide only

7. The pH of a strong acid is closest to… (1 mark) A) 1 B) 7 C) 9 D) 14

8. In an exothermic reaction, the temperature of the surroundings… (1 mark) A) decreases B) stays the same C) increases D) becomes negative

9. Which method separates an insoluble solid from a liquid? (1 mark) A) Evaporation B) Filtration C) Distillation D) Chromatography

10. A metal high in the reactivity series is extracted from its ore by… (1 mark) A) heating with carbon B) electrolysis C) doing nothing D) filtering

Section B — Structured Questions (90 marks)

11. Atoms are the building blocks of all substances. (12 marks) (a) Name the three sub-atomic particles and give the relative charge of each. (6 marks) (b) An atom is written as $^{27}_{13}\text{Al}$. State the number of protons, neutrons and electrons. (3 marks) (c) Explain why this atom has no overall charge. (2 marks) (d) Aluminium is in Period 3. What does the period number tell you about the atom? (1 mark)

12. The periodic table organises the elements. (12 marks) (a) State how the elements are arranged in the modern periodic table. (1 mark) (b) Explain why elements in the same group have similar chemical properties. (2 marks) (c) Describe what you would see when sodium reacts with water. (3 marks) (d) Explain the trend in reactivity as you go down Group 1. (2 marks) (e) Chlorine, bromine and iodine are in Group 7. Describe a displacement reaction between chlorine and potassium bromide solution. (2 marks) (f) Give two properties of transition metals. (2 marks)

13. Atoms join by chemical bonds. (13 marks) (a) Describe how an ionic bond forms between a metal and a non-metal. (3 marks) (b) Explain why ionic compounds have high melting points. (2 marks) (c) Describe how atoms are held together in a covalent bond. (2 marks) (d) Explain why simple molecular substances (like water) have low boiling points. (2 marks) (e) Explain why metals are good conductors of electricity. (2 marks) (f) Graphite conducts electricity. Give one use of graphite that depends on this. (2 marks)

14. Chemists calculate amounts of substances. (11 marks) (a) Calculate the relative formula mass of calcium carbonate, CaCO₃ (Ar: Ca = 40, C = 12, O = 16). (2 marks) (b) State the law of conservation of mass. (1 mark) (c) When magnesium burns, its mass increases. Explain why. (2 marks) (d) Balance the equation: __ Na + __ Cl₂ → __ NaCl (2 marks) (e) Describe how to make pure, dry crystals of a soluble salt from an acid and an insoluble base. (4 marks)

15. Acids react with many substances. (12 marks) (a) Complete: acid + metal → salt + ________ (1 mark) (b) Name the salt made from sulfuric acid and copper oxide. (1 mark) (c) Describe how to measure the pH of a solution. (2 marks) (d) Explain the difference between a strong acid and a weak acid. (2 marks) (e) Describe how a neutralisation reaction works in terms of H⁺ and OH⁻ ions. (2 marks) (f) During electrolysis of copper chloride solution, name the products at each electrode. (4 marks)

16. Reactions involve energy changes. (15 marks) (a) Define an endothermic reaction. (1 mark) (b) Give one use of an exothermic reaction and one use of an endothermic reaction. (2 marks) (c) On a reaction profile for an exothermic reaction, state whether the products are higher or lower in energy than the reactants. (1 mark) (d) Define activation energy. (1 mark) (e) A student measured the temperature change when a metal was added to acid. Describe how they could make sure their results were reliable. (4 marks) (f) Extended response: A student has three unknown metals. Describe how they could use displacement reactions and reactions with acid to put the metals in order of reactivity. (6 marks)

17. This question is about structure, the periodic table and reactions. (15 marks) (a) Define the term isotope. (2 marks) (b) Calculate the relative formula mass of calcium hydroxide, Ca(OH)₂ (Ar: Ca = 40, O = 16, H = 1). (2 marks) (c) Balance the equation: __ Al + __ O₂ → __ Al₂O₃ (2 marks) (d) Explain why reactivity increases going down Group 1. (3 marks) (e) Describe the test, and result, for chlorine gas. (2 marks) (f) Explain why metals are good conductors of electricity. (2 marks) (g) Give two properties of diamond and link them to its giant covalent structure. (2 marks)