Across
- 3. An atom with a different number of neutrons
- 5. The building blocks of matter
- 10. Elements in the same column on the periodic table
- 12. Area around the nucleus where electrons are likely to be found
- 13. Smallest unit of an element
- 16. Particles that orbit the nucleus
- 17. Neutral particle found in the nucleus
- 19. Number of protons in an atom
- 20. Total number of protons and neutrons
Down
- 1. Negatively charged particle
- 2. Charge of the neutron
- 4. Table that organizes all known elements
- 6. Force that holds protons and neutrons together
- 7. Outermost energy level of an atom
- 8. The total negative charge of atom is equal to the number of
- 9. The number of energy levels an atom has shown by its ___ on the periodic table
- 11. Positively charged particle in the nucleus
- 14. The center of an atom
- 15. The scientist who proposed the planetary model of the atom
- 18. Electrons in the outer shell