Match each number to correct letter.
1. protons plus neutron a] atomic mass
2. proton number b] photographic film
3. detects radiation c] atom
4. fixed shape d] electron
5. neutral charge e] atomic number
6. positive charge f] gas
7. occupies the whole container g] solid
8. measures intensity of radiation h] neutron
9. smallest particle to retain characteristics i] proton
10. negative charge j] Geiger counter