A-LevelChemistryChemical periodicityFeb/Mar 2022Paper 1 Q11 Mark
The first ionisation energy of potassium, K, is 418 kJ mol⁻¹. The first ionisation energy of strontium, Sr, is 548 kJ mol⁻¹. Which statement helps to explain why Sr has a greater first ionisation energy than K?
AThe charge on a Sr nucleus is greater than the charge on a K nucleus.
BThe outer electron in a Sr atom experiences greater shielding than the outer electron in a K atom.
CThe outer electron in a Sr atom experiences spin-pair repulsion.
DThe outer electron in a Sr atom is further from the nucleus than the outer electron in a K atom.
✓ Correct Answer
The correct answer is A. This question tests the candidate's understanding of chemical periodicity within the Chemistrysyllabus. The examiner's mark scheme requires...
📋 Examiner Report & Trap Analysis
Common mistake: 62% of candidates selected the distractor because they confused... The examiner specifically designed this question to test whether students can differentiate between... To secure full marks, candidates must demonstrate...
🔒
Unlock the Examiner's Answer
Sign up for free to reveal the correct answer, the official mark scheme breakdown, and the examiner trap analysis for this question.
Sign Up Free to Unlock →Join thousands of Cambridge students already using Oracle Prep