Chemistry A-Level
particle counting
What particle counting means in Chemistry A-Level, as defined for AQA.
Definition of particle counting
Check what you remember
Read the wording for your board, then hide it and explain particle counting in your own words. Rough notes are fine. This is a self-check, with no mark or grade.
Reference: AQA
A three-step routine in which protons equal the atomic number, neutrons equal mass number minus atomic number, and electrons equal protons minus the charge.
Topics that use particle counting
- Mass number and isotopes (AQA A-Level)
Related terms
- abundance ratios
- acceleration to constant kinetic energy
- atomic number
- base peak
- carbon-13 satellite
- charge and electron number
- detection and current
- flight time and mass
Using particle counting in the exam
Check the command word and mark scheme for your exact question. After comparing your explanation with the reference, use the term in an answer on the linked topic. This practice does not predict an exam mark.
Practise Chemistry questions
Create a free account to answer exam-style questions on this topic and get feedback on your answers.
Start free
All Chemistry A-Level termsA week of Premium from your first lesson · Then the free plan continues · No card, no charge