"Is physics harder than chemistry" has no single answer, because the two subjects are hard in different ways, and which way hurts depends on the student. Physics is short on facts and long on maths. Chemistry is the opposite mix. This page explains the difference, compares them at each level, and gives a ten-question check that predicts which one you will find harder.
The difference in one table
| Physics | Chemistry | |
|---|---|---|
| Amount to memorise | Little: a small number of laws and equations | A lot: formulas, reactions, trends, colours, definitions |
| Maths | Heavy, in every topic: algebra, trigonometry, later calculus | Moderate: ratios, moles, logarithms for pH; little in organic chemistry |
| Kind of question | Unfamiliar problems to be set up from a principle | A mix: calculations, explaining a trend, describing a reaction |
| What a typical wrong answer looks like | Could not start, or set up the wrong equation | Forgot a fact, or lost marks on precise wording |
| Variety | One way of thinking, applied everywhere | Three branches (physical, inorganic, organic) that feel like three subjects |
| Lab work | Measuring and uncertainty | Technique, observations, safety |
Put shortly: physics is hard to begin, chemistry is hard to finish. A physics student who has understood Newton's laws can do a great deal with them. A chemistry student keeps meeting new material until the last week of the course.
At each level
US high school. Chemistry is usually taken in 10th or 11th grade and physics in 11th or 12th, an order chosen because physics needs more maths. Most students report physics as the harder of the two, and the reason is almost always algebra: rearranging equations, working with vectors, keeping units straight. Why that happens is laid out in why is physics so hard.
AP. For many years AP Physics 1 had one of the lowest pass rates of any AP exam, although it requires only algebra, because its questions ask for reasoning in words and not just calculation. AP Chemistry covers more content and is usually taken after a first chemistry course. AP Physics C adds calculus and is taken by students who are already strong in maths, so its results look better than its difficulty would suggest.
GCSE and A-level. At GCSE the two are similar in demand; physics has more equations to recall and apply, chemistry more facts. At A-level, physics has less content and harder problems; chemistry has more content, especially organic chemistry. A-level physics without A-level maths alongside it is a noticeably harder course.
CBSE Class 11 and 12. Physics is widely felt to be the hardest of the three sciences, because Class 11 introduces vectors and calculus-based mechanics at once. Chemistry splits into physical (numerical), inorganic (memory) and organic (patterns), and students tend to be good at one and weak in another.
College. First-year physics for scientists and engineers is calculus-based, and it is the maths that separates students. General chemistry is broad and fast; organic chemistry, in the second year, has a reputation as the course that decides who continues to medicine. So at college the honest answer is that each has one famous obstacle.
A ten-question check
Answer yes or no.
- I can rearrange v = u + at to make t the subject without hesitating.
- I like a problem I have never seen before more than a list to learn.
- I draw a diagram before I calculate.
- Sine, cosine and tangent are comfortable.
- I would rather understand one idea deeply than cover many.
- I remember lists, names and exceptions easily.
- I am careful with exact wording in written answers.
- I can keep three topics going at once without mixing them up.
- I like knowing what things are made of and why they react.
- Long calculations with units put me off.
Mostly yes to 1 to 5: you will probably find physics the easier one. Mostly yes to 6 to 10: chemistry. Yes to both sets: take both; they help each other.
Physics against other subjects
| Compared with | Which is harder? |
|---|---|
| Chemistry | Physics to start, chemistry to keep up with |
| Biology | Physics for maths; biology for the amount to learn |
| Calculus | Related, not rivals: calculus is the language physics is written in, and students who take them together find both easier |
| Engineering (college) | Engineering is applied physics with more workload; physics goes deeper into theory |
How hard calculus itself is, course by course, is in is calculus hard.
Which should you take?
- You must choose one, and you want engineering, computer science, architecture or physics: physics.
- Medicine, dentistry, pharmacy, biology, nutrition, veterinary science: chemistry, and most of these want biology too.
- Undecided in the sciences: both, with chemistry first if your maths is still catching up.
- You only need one science credit: choose by the check above, not by reputation.
Do not choose by which is "easier". A subject you find logical takes half the hours of one you have to force.
If you are already struggling
In physics the cause is nearly always one of three things: algebra that is not automatic, not drawing the situation, or memorising equations without knowing when each applies. In chemistry it is usually the mole and its calculations, on which the rest of the course is built, or falling behind on the memory work. Both are found quickly when someone watches you work a problem aloud.
Where to get help
One-to-one online classes in physics and chemistry with tutors who hold master's degrees in the subject: for US high school and AP, GCSE and A-level, IB, and CBSE Class 9 to 12. The first class finds which of the causes above is yours; the classes after it fix that first. The free 30-minute first class is a real lesson on the topic you bring.
Questions parents ask
1Is physics harder than chemistry?
2Is physics harder than chemistry in high school?
3Is physics harder than chemistry at A-level?
4Is physics harder than chemistry and biology?
5Should I take physics or chemistry first?
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