OCR A Level Chemistry A
OCR A Level Chemistry A Periodicity Exam Questions
Free OCR A Level Chemistry A exam questions on Periodicity, with mark schemes. Covers the periodic table, ionisation energies and trends in melting points across periods.
Periodicity exam questions
1 question pack of real past exam questions with its mark scheme. Answer every question without notes, then mark your answers line by line against the mark scheme.
StemUp mark scheme flashcards
OCR A Level Chemistry A H432 Flashcards (Anki & Quizlet)
Every answer is written in mark scheme wording, so you learn exactly what examiners give marks for. Use them on Anki or Quizlet, then test yourself with the questions on this page.
From £10.99View flashcards
About OCR A Level Chemistry A Periodicity
This topic covers periodic trends.
What you need to know
- Structure Periods, groups and blocks.
- Ionisation energy Trends across periods and down groups.
- Melting points Trends linked to structure and bonding across period 3.
- Evidence Successive ionisation energies reveal shells.
Common mistakes in Periodicity
- Forgetting dips in first ionisation energy.
- Saying shielding increases across a period.
- Mixing up giant covalent and simple molecular.
Try three Periodicity exam-style questions
1. Explain why first ionisation energy increases across a period. (2 marks)
Show the mark scheme answer
Nuclear charge increases (1) with similar shielding, so electrons are held more tightly (1).
2. Explain the dip from Mg to Al. (1 mark)
Show the mark scheme answer
Al's outer electron is in a 3p sub-shell, higher in energy.
3. Explain why silicon has a high melting point. (1 mark)
Show the mark scheme answer
Giant covalent structure with many strong bonds.
Periodicity FAQs
What does Periodicity cover?
Periodic trends in ionisation energy and melting point.
What are s, p and d blocks?
Regions based on the sub-shell of the highest energy electron.
Why does sulfur melt higher than phosphorus?
S₈ molecules are larger with stronger London forces.
Revise this topic with flashcards: OCR A Level Chemistry A H432 Flashcards, with mark scheme answers for Anki and Quizlet.
