CAIE IGCSE Chemistry Proton and Atomic Number
Practise defining proton number, reading it from nuclear or particle data and using the proton count to identify an element or compare particles.
- Syllabus
- 2026–2028
- Course
- Chemistry 0620
Practise defining proton number, reading it from nuclear or particle data and using the proton count to identify an element or compare particles.
The table gives the composition of three particles.

What is the evidence in the table for each of the following?
A, B and C are all particles of the same element.
all have the same number of protons / same proton number / same atomic number