Across
- 3. the number that represents the elements place on the table
- 4. the process or result of joining two or more things together to form a single entity
- 7. lightest and most penetrating
- 8. a positive charged particle
- 10. the center of an atom
- 11. the act of emitting radiation spontaneously
- 13. the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei
- 14. the weight of the element
Down
- 1. the time taken for the radioactivity of a specified isotope to fall to half its original value.
- 2. the action of dividing or splitting something into two or more parts.
- 5. a neutral charged particle
- 6. a chemical reaction or other process in which the products themselves promote or spread the reaction
- 9. middle weight and middle penetrating
- 12. heaviest and least penetrating