Across
- 4. A solution with a pH lower than 7
- 5. Table of elements arranged by increasing atomic number
- 6. A gas needed for combustion
- 8. Organic compound mainly made of carbon and hydrogen
- 10. A pure substance made of only one kind of atom
- 12. Smallest unit of an element
- 14. Scientist who proposed atomic theory
- 16. Father of the periodic table
- 17. A type of chemical reaction that absorbs heat
- 18. The simplest and lightest element
- 19. A positively charged ion
- 20. Atomic number of Oxygen
- 21. Scientist who discovered radioactivity
- 22. Type of bond formed by sharing electrons
Down
- 1. Process of a solid turning directly into gas
- 2. Table that organizes elements
- 3. Negatively charged particle
- 7. Type of reaction where heat is released
- 9. Law Law relating the pressure and volume of a gas
- 11. Measure of an atom's attraction for electrons
- 12. The chemical symbol for gold
- 13. Measurement unit of the amount of substance
- 15. Amedeo, known for a gas law