📋 Structured Questions
These questions test key concepts from Topic 1. Attempt each question on paper, then click "Show Mark Scheme" to check your answer.
Question 1: Group 1 vs Transition Metals
2 marks(a) Give two differences between the physical properties of the elements in Group 1 and those of the transition elements. [2]
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Any two from:
- Group 1 elements have lower melting/boiling points [1]
- Group 1 elements have lower densities [1]
- Group 1 elements are less strong / softer [1]
Question 2: Models of the Atom
3 marksThe plum pudding model did not have a nucleus.
(a) Describe three other differences between the nuclear model of the atom and the plum pudding model. [3]
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Any three from:
- The nuclear model is mostly empty space [1]
- The positive charge is concentrated in the nucleus [1]
- The mass is concentrated in the nucleus [1]
- The electrons and the nucleus are separate / electrons orbit the nucleus [1]
Question 3: Halogen Reactivity
3 marks(a) Explain why the reactivity of the halogens decreases going down Group 7. [3]
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- Going down the group, the outer electrons become further from the nucleus / the atoms become larger [1]
- The nucleus has less attraction for the outer electrons [1]
- An electron is gained less easily [1]
Question 4: Chadwick's Discovery
3 marks(a) Chadwick's experimental work on the atom led to a better understanding of isotopes. Explain how his work led to this understanding. [3]
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- Chadwick provided evidence to show the existence of neutrons [1]
- Isotopes are atoms of the same element / have the same number of protons [1]
- But with different numbers of neutrons [1]
Question 5: Mendeleev's Periodic Table
4 marks(a) The atomic weight of tellurium (Te) is 128 and that of iodine (I) is 127. Why did Mendeleev reverse the order of these two elements? [1]
(b) Mendeleev left spaces for undiscovered elements. Explain why Mendeleev's periodic table became more widely accepted than previous versions. [3]
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(a) So elements were in groups with similar properties / Iodine has similar properties to Group 7 elements [1]
(b)
- Mendeleev had predicted properties of missing elements [1]
- Elements were later discovered that filled the gaps [1]
- The properties of these elements matched Mendeleev's predictions [1]
Question 6: Isotopes
4 marks(a) Give the meaning of 'isotopes'. You should answer in terms of subatomic particles. [2]
Gallium (Ga) is in Group 3. The isotope Gallium-69 has an atomic number of 31.
(b) Give the numbers of electrons and neutrons in an atom of Gallium-69. [2]
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(a) (Atoms with the) same number of protons [1] (but with) different numbers of neutrons [1]
(b) 31 electrons [1], 38 neutrons (69 − 31 = 38) [1]
Question 7: Development of the Atomic Model ⭐ Extended Response
6 marksThe model of the atom has developed over time as new experimental evidence was discovered.
(a) Describe the differences between the plum pudding model and the nuclear model of the atom, and explain how the results of the alpha particle scattering experiment led to the nuclear model. [6]
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Level 3 (5–6 marks): A detailed, coherent comparison between the two models with specific evidence from the alpha scattering experiment linked to the conclusions of the nuclear model.
Level 2 (3–4 marks): Relevant features of both models identified with some valid comparisons. Clear attempt to link the scattering experiment to the nuclear model, though may lack fine detail.
Level 1 (1–2 marks): Basic information about either atomic model or the scattering experiment. Lacks clear linkages or comparison.
Indicative content:
- Plum pudding model: atom is a ball of positive charge with negative electrons embedded throughout; no empty space
- Nuclear model: mass concentrated in a tiny positive nucleus; electrons orbit at specific distances/shells; atom is mostly empty space
- Evidence: most alpha particles passed straight through → atom is mostly empty space
- Small proportion deflected at large angles or bounced back → tiny, concentrated positive nucleus
Question 8: Required Practical — Chromatography 🔬
4 marksA student uses paper chromatography to investigate the dyes present in three food colourings.
(a) Describe the method the student should follow to carry out this chromatography experiment. [4]
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- Draw a pencil baseline on chromatography paper (not pen, as ink would dissolve) [1]
- Place a small spot of each food colouring on the baseline [1]
- Place the paper in a beaker of solvent (water) with the solvent level below the baseline [1]
- Allow the solvent to travel up the paper; remove and dry when solvent nears the top [1]
Question 9: Required Practical — Simple Distillation ⭐🔬 Extended Response
6 marksA student has a sample of ink (a mixture of a dye dissolved in water). They want to obtain a sample of pure water from the ink.
(a) Describe the method the student should use to obtain pure water from the ink using distillation. Explain why each step is necessary. [6]
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Level 3 (5–6 marks): Detailed, logically sequenced description of the distillation method with clear explanations of why each step is carried out (heating, evaporation, condensation, collection).
Level 2 (3–4 marks): Describes most steps correctly but may not explain why each step works, or may miss a key procedural detail.
Level 1 (1–2 marks): Basic statements about heating or collecting water, lacking a logical sequence or scientific explanations.
Indicative content:
- Pour the ink into a round-bottomed flask; heat with a Bunsen burner
- Water has a lower boiling point than the dye, so the water evaporates first
- Water vapour passes into a Liebig condenser (cooled by cold water flowing through the jacket)
- The vapour condenses back into liquid pure water and is collected in a beaker
- The dye remains in the flask as it has a higher boiling point
- To confirm purity: check the water boils at exactly 100°C