Chemistry Crossword

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

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