Across
- 3. time needed for half of substance to decay
- 4. antimatter counterpart of the electron
- 9. radiation = helium nucleus (He)
- 10. number of protons, identifies elements
- 13. fundamental particles like electrons & neutrinos
- 15. same mass, opposite charge of counterpart
- 19. particle composed of a quark and an anti-quark
- 20. positive nucleon
- 22. combining light nuclei
- 23. particles that make up nucleons
- 24. defect difference in mass between the nucleus and its constituent particles
- 26. unit of light energy
Down
- 1. building block of nucleus
- 2. number of protons plus neutrons
- 5. particles given off in radioactivity
- 6. splitting of heavy nuclei
- 7. nuclide nuclide present after radioactive decay
- 8. radiation = high energy photon (γ)
- 11. negatively charged lepton
- 12. tiny neutral particles (leptons)
- 14. tiny, dense, positive center of atom containing protons and neutrons
- 16. force – holds nucleus together, overcomes repulsive electrostatic force
- 17. radiation = electron or positron (e)
- 18. particle composed of quarks
- 21. neutral nucleon
- 25. atoms with same atomic number, different mass numbers