James Puzzle

2. reaction, a process that involves the arrangement of the molecular or ionic structure of a substance
4. equation, a symbolic representation of a chemical reaction in symbols
5. change, when a substance combines with another to form a new substance
7. a substance produced by a living organism which acts as a catalyst to bring about a specific biochemical reaction
10. reaction, a chemical reaction that releases energy through light or heat
11. a substance that increases the rate of chemical reaction
12. a thing that is composed of two different elements
14. a mixture that is not evenly mixed
15. a stable subatomic particle occering in all atomic nuclei with a positive charge
16. a substance that slows down or prevents a particular chemical reaction
19. a stable subatomic particle with a negative charge
20. mass, a mass of an atom of a chemical element expressed in an atomic mass unity

1. change, it affects the form of a chemical substance but not its chemical composition
3. that which occupies space and possesses mass
6. an element is a substance that is made entirely from one type of atom
8. a process that requires or absorbs energy from its surrounding ie heat
9. mixture, two or more substances that have been mixed completely
13. a substance made by mixing other substances together
17. a subatomic particle of about the same mass as a proton but without an electrical charge
18. the basic unit of a chemical element