GCSE Chemistry Daily Practice (Foundation)
Mark Scheme — 17 marks total
Foundation TierMarking Instructions
- • Accept equivalent answers unless the mark scheme states otherwise.
- • M marks are for method — award even if the final answer is wrong.
- • A marks are for accuracy — only award if the method mark has been earned.
- • B marks are independent and can be awarded without other marks.
- • Where a range of answers is acceptable, this is indicated in the mark scheme.
Atomic Structure
9 marksAn atom of potassium has atomic number 19 and mass number 39. State the number of protons, neutrons, and electrons.
Acceptable Answer
Protons: 19, Neutrons: 39 - 19 = 20, Electrons: 19
Explain why elements in Group 1 become more reactive as you go down the group.
Acceptable Answer
Going down the group, atoms have more electron shells. The outer electron is further from the nucleus with more shielding. The attraction between the nucleus and outer electron is weaker, so it is lost more easily. Easier loss of electron = more reactive.
Explain why ionic compounds conduct electricity when molten but not when solid.
Acceptable Answer
In solid state, ions are held in fixed positions in the lattice — they cannot move to carry charge. When molten, the lattice structure breaks down, ions become free to move and can carry electric charge.
Chemical Reactions
8 marksBalance: Fe + Cl₂ → FeCl₃
Acceptable Answer
2Fe + 3Cl₂ → 2FeCl₃
Describe what happens when zinc is added to copper sulfate solution.
Acceptable Answer
Zinc is more reactive than copper. Zinc displaces copper from the solution. The blue solution turns colourless as copper sulfate is replaced by zinc sulfate. Brown copper metal is deposited. Zn + CuSO₄ → ZnSO₄ + Cu
Describe the test for hydrogen gas and carbon dioxide.
Acceptable Answer
Hydrogen: hold a burning splint near the gas — it burns with a squeaky pop. Carbon dioxide: bubble through limewater — it turns milky/cloudy.