Across
- 1. H on periodic table
- 5. the smallest unit of a chemical element
- 7. a group of two or more atoms that are held together by attractive forces
- 8. O on periodic table
- 13. when chemicals react to make new chemicals
- 16. Ions that are Positive
- 17. a basic substance that cannot be broken down into simpler substances by ordinary chemical processes
- 18. Positively charged
- 19. a homogeneous mixture
- 20. Number of protons
Down
- 2. a higher energy level of an atom
- 3. Neutral (not positive or negative)
- 4. attractive and repulsive forces that arise between the molecules of a substance
- 6. a atom or group of atoms that has an electric charge
- 9. Negatively charged
- 10. Atoms with the same number of protons but different numbers of neutrons
- 11. table a table of the chemical elements arranged in order of atomic number
- 12. One or two substances
- 14. What some symbols of periodic table or named as
- 15. two or more different elements together