Sicence

1. "When on element replaces another in a compound, or when two elements in different compounds trade places."
3. a material that increases the rate of reaction by lowering the activation energy."
5. "is anything that has mass and takes up space."
7. The cells in your body contain biological catalysts called ENZYMES."
9. equation-"is a short, easy way to show a chemical reaction, using symbols instead of words."
11. "is a amount of a substance in a given volume."
13. system- " matter is not allowed to enter or leave."
15. " A solid that form's from solution during a chemical reaction."
16. "A material used to decrease the rate of a reaction"
17. of mass- "during a chemical reaction, matter is not created or destroyed
18. "when two or more elements or compounds combine to make more complex substances the process is called synthesis."
20. system- "matter can enter from or escape to the surrounding."
23. property- A characteristic of a substance that can be observed without changing the substance into another substance.
24. "is a number placed in font of chemical formula in an equation."

2. reaction- "is a reaction in which energy is absorbed
4. " a rapid reaction between oxygen and a substance called a fuel.
6. The substance you have at the beginning"
8. change- " is any change that alters the form or appearance of a substance but that does not make the substance into another substance.
10. "When the reaction is complete, you have new substances"
11. "The study of matter and how matter changes"
12. energy- "is a minimum amount of energy needed to start a chemical reaction."
14. "In contrast to a synthesis reaction, a process called DECOMPOSITION breaks down compounds into simpler products."
17. reaction- A change in matter that produces one or more new substances.
19. reaction-"A reaction that releases energy in the form of heat"
21. is a material that releases energy when it burns."
22. property- a Characteristic of substance that describes its ability to change into other substances.