Mini practice paper: 8 questions
Mixed-difficulty questions from across the Chemistry syllabus. Tap "Show answer" after each to check yourself.
Q1 · Difficulty 1/3
Which of the following is a characteristic property of transition metals that distinguishes them from Group 1 metals?
- A: They react vigorously with cold water
- B: They form coloured compounds
- C: They have low melting points
- D: They have only one possible oxidation state
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✓ Answer: B — B: They form coloured compounds
Transition metals are characterised by forming coloured compounds due to their partially filled d-subshells. Group 1 metals react vigorously with cold water, have relatively low melting points, and form compounds in only one oxidation state (+1), none of which are typical transition metal properties.
Q2 · Difficulty 1/3
A student adds sodium hydroxide solution to a solution of copper(II) sulfate. What is the colour of the precipitate formed?
- A: Red-brown
- B: White
- C: Blue
- D: Green
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✓ Answer: C — C: Blue
When sodium hydroxide solution is added to a copper(II) sulfate solution, a blue precipitate of copper(II) hydroxide forms. Red-brown precipitate is characteristic of iron(III) hydroxide, while iron(II) hydroxide gives a green precipitate.
Q3 · Difficulty 1/3
An atom of carbon has an atomic number of 6 and a mass number of 12. How many neutrons does it contain?
- A) 6
- B) 12
- C) 18
- D) 2
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✓ Answer: A — A) 6
The number of neutrons is calculated by subtracting the atomic number from the mass number: 12 − 6 = 6 neutrons. A common error is to confuse mass number with the number of neutrons directly.
Q4 · Difficulty 2/3
Uranium has two isotopes: U-235 and U-238. Compared to U-235, U-238 has:
- A) More protons and the same neutrons
- B) The same protons and more neutrons
- C) Fewer protons and more neutrons
- D) More protons and more neutrons
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✓ Answer: B — B) The same protons and more neutrons
Both isotopes have the same atomic number (92 protons) because they are both uranium. U-238 has 238 − 92 = 146 neutrons, while U-235 has 235 − 92 = 143 neutrons, giving U-238 three more neutrons.
Q5 · Difficulty 2/3
An element X has atomic number 17 and mass number 35. Which of the following correctly describes a neutral atom of X?
- A) 17 protons, 17 neutrons, 18 electrons
- B) 17 protons, 18 neutrons, 17 electrons
- C) 18 protons, 17 neutrons, 17 electrons
- D) 17 protons, 35 neutrons, 17 electrons
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✓ Answer: B — B) 17 protons, 18 neutrons, 17 electrons
Atomic number 17 means 17 protons. In a neutral atom, electrons = protons = 17. Neutrons = mass number − atomic number = 35 − 17 = 18. Option A incorrectly gives 18 electrons, suggesting a charged ion.
Q6 · Difficulty 2/3
A student compares a 1 cm cube of gold to gold nanoparticles of the same total mass. Which statement correctly describes the nanoparticles?
- They have fewer atoms exposed on the surface
- They have a lower total surface area
- They have a greater surface area to volume ratio
- They have a higher melting point than bulk gold
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✓ Answer: C — They have a greater surface area to volume ratio
Dividing a bulk material into nanoparticles dramatically increases the surface area to volume ratio because far more atoms are exposed at surfaces. This is a fundamental concept explaining why nanoparticles have enhanced reactivity and different properties. Nanoparticles generally have lower, not higher, melting points than the bulk material.
Q7 · Difficulty 3/3
Calculate the surface area to volume ratio of a nanoparticle modelled as a cube with a side length of 4 nm.
- 0.5 nm⁻¹
- 1.5 nm⁻¹
- 6 nm⁻¹
- 1 nm⁻¹
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✓ Answer: B — 1.5 nm⁻¹
Surface area of a cube = 6 × (4)² = 96 nm². Volume = (4)³ = 64 nm³. Ratio = 96 ÷ 64 = 1.5 nm⁻¹. This calculation demonstrates how the ratio is determined; at the nanoscale these values are extremely large compared to macroscopic objects.
Q8 · Difficulty 3/3
A 0.500 g sample of a transition metal compound contains 0.200 g of iron. What is the percentage by mass of iron in the compound?
- A: 20.0%
- B: 40.0%
- C: 25.0%
- D: 50.0%
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✓ Answer: B — B: 40.0%
Percentage by mass = (mass of iron ÷ total mass of compound) × 100 = (0.200 ÷ 0.500) × 100 = 40.0%. A common error is to divide the total mass by the mass of iron rather than the other way around, giving the incorrect answer of 250%, or to forget to multiply by 100.
AQA GCSE Chemistry FAQ
What does the AQA GCSE Chemistry exam look like?
The AQA GCSE Chemistry exam is structured across 3 components. Paper 1: Approximately 1 hour 30 minutes, ~70-100 marks. Covers Topics 1-4 of the specification. Paper 2: Approximately 1 hour 30 minutes, ~70-100 marks. Covers Topics 5-8 of the specification. Paper 3: Where applicable — e.g. Combined Science, Languages. Includes synoptic and applied questions. Total exam time: ~3 hours across two or three papers.
Can I download a free AQA GCSE Chemistry past paper?
Real AQA past papers are published directly by AQA on their official website. Kramizo doesn't redistribute copyrighted past papers, but we do generate free AI-written practice papers in the exact same style — same command words, same difficulty tier, same mark conventions. Use this practice paper as warm-up, then time yourself on official past papers before exam day.
How is AQA GCSE Chemistry graded?
Grades: 9 (highest) to 1 (lowest), with U (ungraded). A grade of 4 is a standard pass; 5 is a strong pass. Kramizo's practice questions are tagged with difficulty 1-3 mapping roughly to the lower, middle, and top grade boundaries you'll encounter in the real exam.