Across
- 2. The smallest part of an element
- 3. The sum of protons and neutrons in an atom
- 4. The most stable and nonreactive elements
- 5. A change that results when two or more substances react to create a different substance or substances; the new substances have completely different properties from the original ones
- 9. A chemical reaction that occurs when oxygen reacts with a substance to form a new substance and give off energy
- 11. A combination of symbols that represent a compound; the formula identifies the elements in the compound and the amount of each element
- 13. Invisible negatively charged particle that orbits the nucleus of an atom
- 17. The ability of a substance to conduct electricity or heat
- 18. Substance that helps a chemical reaction to proceed more quickly
- 19. A pure substance formed when two non-metals combine
- 21. A cloudy mixture that cannot be separated out from the other substance
- 22. A slow chemical change that occurs when oxygen in the air reacts with a metal
- 24. The most reactive non-metal
- 25. An atom that has become electrically charged by losing or gaining electrons
Down
- 1. An experiment in which all reactants and all products of a chemical reaction are accounted for
- 6. A reaction that takes place when two or more substances react to form new substances
- 7. The mass of one atom
- 8. The most reactive of metals
- 10. A pure substance formed when a metal and non-metal combine
- 12. A chemical combination of two or more elements in a specific ratio
- 14. The vertical columns in the periodic table
- 15. The number of protons in the nucleus of one atom of an element
- 16. An element that has both metallic and non-metallic properties
- 20. Orbit of electrons around the nucleus of an atom
- 23. A pure substance that cannot be broken down into other substances; substance made up of only one type of atom