The World’s Premier Chemistry Competition for Students
IChO is an annual academic competition that gathers the brightest secondary-school chemists from 80+ countries to tackle advanced theoretical and experimental problems in chemistry.
Founded
1968 • Prague, Czechoslovakia
Participants
80+ countries • 300+ students / year
Format
Two 5-hour exams: Practical + Theoretical
Team
Up to 4 students + 2 mentors per country
Purpose & Mission
- Inspire a deep interest in chemistry among young students.
- Develop problem-solving through challenging theoretical and experimental tasks.
- Promote international collaboration and cultural exchange.
- Build lifelong friendships and strengthen global cooperation in science and education.
Competition Structure
Delegations
Each country sends up to 4 students and 2 mentors (one as Head Mentor). Scientific observers and guests may also attend.
Examinations
- Practical (Experimental) — laboratory techniques, data analysis, and experimental problem-solving.
- Theoretical — advanced topics across all areas of chemistry.
Each exam lasts five hours and emphasizes knowledge, creativity, and critical thinking.
Awards & Recognition
IChO recognizes individual excellence. Students are ranked by overall score and may receive:
- Gold, Silver, and Bronze Medals
- Honourable Mentions
- Special Awards — Highest Overall Score, Best Theoretical, Best Practical
Global Reach
From a 3-country start in 1968, IChO now brings together hundreds of students from 80+ nations annually. Hosting rotates each year, giving participants the chance to discover new cultures, build international friendships, and experience world-class scientific collaboration.
Key Facts
| Founded | 1968 (Prague, Czechoslovakia) |
|---|---|
| Participating Countries | 80+ nations from all continents |
| Annual Participants | 300+ students |
| Competition Format | Two exams: 5-hour Practical + 5-hour Theoretical |
| Medal Distribution | Gold ≈ top 12%, Silver ≈ next 22%, Bronze ≈ next 32% |
| Special Awards | Highest Overall • Best Theoretical • Best Practical |
| Hosting System | Organized by a different country every year |
| Team Structure | Up to 4 students + 2 mentors per country |
| IChO Flag Symbolism | Five flames: Thallium (green), Calcium (orange), Sodium (yellow), Copper (blue-green), Strontium (red) |