An atom’s nucleon number is usually larger than its proton number. The gap between these two values shows the number of ......1...... in the atom. Atoms with the same proton number but different nucleon numbers are known as ......2...... . Which words would correctly fill gaps 1 and 2?
- Aelectrons; isomers
- Belectrons; isotopes
- Cneutrons; isomers
- Dneutrons; isotopes