Across
- 2. The most weakly penetrating form of radiation
- 5. When isotopes release radiation
- 7. Radiation with a charge of -1
- 11. When gamma rays excite electrons, causing them to leave an atom
- 14. Atoms with the same number of protons but different numbers of electrons
- 17. One in 8000 alpha particles bouncing back indicated that the nucleus was very small and _____
- 18. Gamma rays are not particles, we define them as
Down
- 1. John Dalton's model of the atom is known as the...
- 3. Time taken for half of the nuclei of a radioisotope to decay
- 4. Who discovered the electron?
- 6. The material that will stop beta particles
- 8. An example of a radioistope is _____238
- 9. Scientist who came up with Plum pudding model
- 10. Atoms that have become charged due to the loss of electrons
- 12. The philosopher who first came up with the concept of atoms
- 13. The _____ number drops by two in alpha decay
- 15. Atoms are mostly made up of...
- 16. Type of radiation that consists of a high-speed electron