Overview
The United States National Chemistry Olympiad (USNCO) is a multi-stage high-school chemistry competition sponsored by the American Chemical Society (ACS). Local competitions, organised with ACS Local Sections, feed a National Exam taken by more than 1,000 students. The 20 top scorers attend a study camp, and four students from the camp are chosen to represent the USA at the International Chemistry Olympiad (IChO), which is hosted in July by one of the participating countries.
Who can apply
Local competitions are open to all high-school students in the USA. A student may compete only in the local section where their high school is located.
To take the National Exam, a student must be a US citizen or a permanent resident (green card holder). Other students can take the local exam but cannot be nominated for the National Exam, whatever their score.
Students in grades 9 to 12 who will graduate no earlier than 1 May of the competition year are eligible.
A student must be under 20 on 1 July of the competition year.
Students who have taken Advanced Placement chemistry are eligible.
No more than two students per school can be nominated for the National Exam.
Previous study camp attendees who are still eligible go straight to the National Exam, and do not count against the nominee limits.
IChO gold medallists cannot take part again in the National Exam, study camp or IChO.
US citizens living abroad can take part through a competition organised by an ACS International Chemical Sciences Chapter, if they have been enrolled in an American school for at least a year and are under 20.
Exam pattern
| Stage | Format |
|---|---|
| Local exam | 60 multiple-choice questions, 110 minutes, broad chemistry topics |
| National Exam, Part I | 60 multiple-choice questions, 90 minutes, broad chemistry topics |
| National Exam, Part II | 8 written problem-solving questions, 105 minutes, chemical theories and models |
| National Exam, Part III | 2 laboratory practicals, 90 minutes |
Only non-programmable calculators without on-board memory may be used, if a calculator is used at all. Phones and any device that can reach the internet, copy or photograph, or hold stored information are grounds for disqualification.
Syllabus
The multiple-choice papers, local and national, are split into ten six-question blocks: stoichiometry and solutions, descriptive and laboratory chemistry, states of matter, thermodynamics, kinetics, equilibrium, oxidation-reduction, atomic structure and periodicity, bonding and molecular structure, and organic and biochemistry.
Marking and results
ACS compares each student's score in a topic with the overall average and rates it as below average, average, above average or outstanding. Only Part I scores are sent to local coordinators to pass on to students. Roughly the top 50 students are named High Honors and the next 100 Honors, and the lists are published on the USNCO website.
How to apply
Find your USNCO Coordinator through the ACS lookup tool. A parent or guardian must register the student with ACS on the USNCO registration platform; this includes home-schooled students. Registration does not guarantee a place, and coordinators tell students whether they were confirmed. Coordinators nominate students for the National Exam from local results, within a quota set by the number of ACS members in each local section.
After the exam
The 20 top National Exam scorers spend two weeks in June at a study camp. Based on camp performance, four students are chosen for the IChO team.
Preparation tips
Practise past local and national exams, which ACS publishes.
Work evenly through all ten multiple-choice topic blocks.
Build laboratory skills for Part III.
Can an international student take the National Exam?
Only US citizens and permanent residents can take the National Exam. Other students may take the local exam.
Who goes to the study camp?
The 20 top-scoring students on the National Exam.