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Electron shells, group and period

Electron shells, group and period

Sodium atom with atomic number 11, electron arrangement 2,8,1, Group 1 and Period 3

Atoms have a tiny nucleus containing protons and neutrons, with electrons arranged in shells around it. In a neutral atom, the atomic number tells you both the number of protons and the number of electrons.

Bonding Lesson

  1. GCSE
  2. /Chemistry
  3. /Bonding

Step-by-step lessons covering OCR GCSE Chemistry Bonding for Foundation and Higher tier. Each lesson works through exam-style questions in Paper 1 and Paper 2 (Foundation Tier) or Paper 3 and Paper 4 (Higher Tier) format. Nail the core quantitative topics — moles, balancing equations and calculations — early on, since they underpin higher-tier questions across every paper and topic.

Lessons