Skip to content

πŸ‡¬πŸ‡§ Cambridge Chemistry Challenge (C3L6)

Cambridge Chemistry Competition for Lower Sixth

Overview

The Cambridge Chemistry Challenge (C3L6) is a national chemistry competition organized by the University of Cambridge Department of Chemistry, co-sponsored by St Catharine's College, Cambridge. Created by Professor Peter Wothers, the competition is designed to stretch students beyond the A-Level syllabus and ease the transition to university-level chemistry. The target audience is UK students in Year 12 (Lower Sixth) or below.

The name "C3L6" derives from "Cambridge Chemistry Competition for Lower Sixth." With over 13,000 UK participants and 10,000+ international participants annually, it is one of the largest school-level chemistry competitions in the UK.

Key Website

Competition Format

  • Duration: 90 minutes
  • Format: Written paper taken under exam conditions at the student's school
  • Structure: 2–3 extended chemistry problems with roughly a dozen sub-questions
  • Difficulty: Questions push students "significantly beyond the syllabus" and illustrate chemistry in everyday-life contexts
  • Marking: Papers are marked centrally by Cambridge; results are returned within approximately 60 days

Awards

Award Cutoff Prize
Roentgenium Top ~0.5% (~54–70 students) Invitation to a 3-night residential camp at St Catharine's College
Gold Top 10% Certificate
Silver Top 30% Certificate
Copper Top 60% Certificate

The top 60% of participants earn certificates. The Roentgenium Award β€” named after element 111 (roentgenium), the next element in the copper-silver-gold group β€” is the highest honour. Roentgenium winners receive an invitation to a three-night residential camp at St Catharine's College featuring laboratory practicals, lectures, small-group problem solving, and a formal dinner.

Relationship to IChO

C3L6 is described as a "pre-test" or stepping stone to the UK Chemistry Olympiad (UKChO). UKChO is the continuation competition of C3L6 and serves as the UK's selection pathway for the International Chemistry Olympiad (IChO). Many students who excel at C3L6 go on to compete in UKChO and eventually represent the UK at the IChO.

Student Outcomes

The residential camp experience frequently motivates participants to apply to Cambridge. Past C3L6 attendees commonly return as undergraduate helpers, and the competition is widely regarded as a strong signal on university applications to Cambridge, Oxford, and other top institutions. The Roentgenium Award in particular is a prestigious credential for STEM university admissions.

International Version

C3L6 is administered internationally through partner organizations (notably ASEEDER in China/Asia). International students in Grades 9–11 may participate but cannot register through British schools. An Asia Camp is held in China for regional winners, and a limited number (up to 35) of international Gold awardees are invited to the St Catharine's College camp in Cambridge.

History

  • ~2010–2011 β€” C3L6 first held (a 2011 past paper exists; St Catharine's College reported in 2021 that C3L6 had been running for 11 years)
  • Early years β€” Began with online puzzle challenges (180 puzzles over five years) before evolving into a formal written examination
  • Present β€” Over 13,000 UK students and 10,000+ international students participate annually
  • 2021 β€” 54 Roentgenium Awards given from 7,000+ UK competitors

Sources