Across
- 3. A number in front of a chemical formula in an equation that indicates how many molecules or atoms of each reactant and product are involved in a reaction.
- 4. system A system in which no matter is allowed to enter or leave
- 7. A reaction in which one element replaces another in a compound or when two elements in different compounds trade places
- 9. A solid in which the atoms arranged in a pattern that repeats again and again.
- 10. A substance formed as a result of a chemical reaction.
- 11. A chemical reaction that breaks down compounds into simpler products.
- 14. reaction A reaction that absorbs energy.
- 18. A type of protein that spreads up a chemical reaction in a living thing a biological catalyst.
- 19. A material that decreases the rate of a reaction.
- 20. conservation mass The principle that the total amount of matter is neither created nor destroyed during any chemical or physical change.
Down
- 1. equation A short easy way shows a chemical reaction using symbols.
- 2. The amount of one material in a certain volume of another material.
- 5. system A system in which can enter from or escape to the surroundings.
- 6. reaction A reaction that releases energy usually in the form of heat.
- 8. A solid that forms a solution during a chemical reaction.
- 12. A chemical reaction in which two or more simple substances combine to form a new more complex substance.
- 13. energy The minimum amount of energy needed to start a chemical reaction.
- 15. A Substance that enters into a chemical reaction.
- 16. change A change in which one or more substances combine or break apart to new substances.
- 17. change A change that alters the form or appearance of material but does not make the material into another substance.