← 1.5 Periodicity

Atomic radius across a period

Chemistry · Grade 10 · about 40 minutes

Across a period atoms shrink because extra protons pull the same shells inward.

Sign in to read this lesson

Lessons are for learners and teachers with an account. Browsing the curriculum — subjects, strands and what each sub-strand covers — stays open to everyone.

  • 6 sections of explanation, worked examples and diagrams
  • 1 practice task with hints and worked answers
  • A quiz that marks itself as you go
  • Your progress kept across every subject you take
Sign in Create an account