Chemistry · May / June 2026 · Paper 11 · Question 3

The difference between the nucleon number and the proton number indicates the number of ......1...... in the atom. Atoms that have different nucleon numbers but the same proton number are called ......2...... . Which words correctly complete gaps 1 and 2?

1. A1 electrons, 2 isomers
2. B1 electrons, 2 isotopes
3. C1 neutrons, 2 isomers
4. D1 neutrons, 2 isotopes

As printed in the paper