Chemistry Crossword

3. releases heat energy.
6. a table in which the elements are organized by their physical and chemical properties.
10. a change where two or more substances react to create a new substance.
12. a mixture of two or more pure substances that look like one.
15. number of protons in the nucleus in one atom of an element.
18. mass of one atom or an element.
20. absorbs heat energy.
22. a substance that reacts with another substance or substances in a chemical reaction to create a new substance with different products or properties.

1. substance that helps speed up a chemical reaction.
2. a combination of pure substances, not a compound.
4. a chemical reaction that occurs when oxygen reacts with a substance to form a new substance, the process is fast.
5. group one elements in the periodic table.
6. a substance made up of only one kind or matter, which has a unique set of properties.
7. a pure substance that cannot be broken down into other substances, only one type of atom.
8. a change that results when two or more substances react to create a different substance.
9. a change in appearance or state of a substance that does not change composition.
10. an experiment in which all the reactants and all products of a chemical reaction are accounted for.
11. a cloudy mixture where tiny particles of one substance are held within another and the particles cannot be separated out of the other substance.
13. chemical combination of two or more elements in a specific ratio.
14. a new substance produced in a chemical reaction between reactants.
16. an atom or a group of atoms that has become electrically charged because it has lost or gained electrons.
17. group 17 elements on the periodic table.
19. is a slow chemical change that occurs when oxygen in the air reacts with a metal.
21. an experiment in which one or more products of a chemical reaction can escape.