Chemistry Crossword

3. an experiment in which all products of a chemical reaction are accounted for
6. chemical combination of two or more elements in a specific ratio
7. a colourless, odorless, poisonous gas
10. substance that helps a chemical reaction proceed more quickly
11. number of protons in the nucleus of one atom as an element
13. the smallest part of an element that is representative of that element
14. change that results when two or more substances react to form a new substance
15. measure of atomic mass
16. combination of symbols that represent a compound
17. ability of a substance to conduct electricity or heat
18. mass of one atom of an element calculated from the total number of protons, neutrons, and electrons in an atom
19. atom that has become electrically charged because it lost or gained electrons
20. principle that matter is not created or destroyed in a reaction
22. group 1 elements in the periodic table, not including hydrogen; the most reactive of the elements

1. invisible negatively charged particle that orbits around the nucleus of an atom
2. pure substance formed when at least one metal and one non-metal combine
4. material that electric charge can move through easily
5. pure substance that cannot be broken down into other substances
8. group 2 elements in the periodic table: their reactivity is not as strong as that of alkili metals
9. vertical column of elements in the periodic table
10. a reaction that takes place when two or more substances to form a new substance
12. group 17 elements in the periodic table: the most reactive non-metal
14. chemical reaction that occurs when oxygen reacts with a substance to form a new substance and give off energy
20. energy stored in chemicals and released when chemicals react
21. vertical column of elements in periodic table