Across
- 2. Basic unit of matter
- 3. The total number of protons and neutrons
- 11. The smallest unit of a chemical compound
- 13. Pure substances made up of one atom
- 16. Positively charged atomic particle
- 17. Molecule composed of the same element bonded together.
- 18. Columns of the modern table
Down
- 1. The number of protons in an atom
- 4. Elements with metal and nonmetal properties
- 5. Atoms with the same number of protons but different numbers of neutrons
- 6. Elements that cannot conduct electricity
- 7. The substance that physical objects are made of
- 8. Center of the atom
- 9. Neutrally charged atomic particle
- 10. Negatively charged atomic particle
- 12. a substance made of two or more elements
- 14. Elements that can conduct electricity
- 15. Rows of the periodic table