Chemistry crossword

2. Substance that helps a chemical reaction to proceed quicker
6. Combination of symbols that represent a compound, it identifies the elements in a compound and the amount of each element
9. Solid to gas
12. A chemical reaction that occurs when oxygen reacts with a substance to form a new substance and give off energy
13. Pure substance formed when two non-metals combine
15. Substance that greatly resists the flow of electricity
16. Catalyst involved in a chemical reactions in living thing
19. An experiment in which one or more products of a chemical reaction can escape
20. Smallest part of an element that is representative of that element
21. group of 17 elements in the periodic table. Most reactive non-metals

1. A material that is made up of one substance
2. A change that occurs when 2 or more substances react to create a new substance
3. Characteristics that can be used to describe a substance
4. Horizontal row of elements in the periodic table
5. Describes the physical appearance and composition of a substance
6. Describes how a substance reacts with other other substances
7. Pure substance formed when at least one metal and non-metal combine
8. Chemical combination of two or more elements in a specific ratio
10. A material that electric charge can move through easily
11. New substance produced in a chemical reaction between reactants
13. Shiny, malleable, ductile, element that conducts electricity
14. The number of protons in a nucleus of one atom in an element
17. Anything that has mass and takes up space
18. The mass of one atom in an element, made up of protons, neutrons and electrons