Across
- 2. amount of energy needed for a reaction to start
- 4. outermost electrons of an atom
- 7. how the "arrow" in a chemical reaction is read
- 9. type of chemical equation that has the same number of atoms of each element on both sides of the arrow
- 10. starting substances
- 13. the number in front each substance in a reaction (can be change)
- 14. type of chemical reaction where a complex reaction breaks down into simple products
- 15. number of elements in a compound (can not be changed)
- 18. ending substances
- 19. every element has a _________ represented by 1 or 2 letters
Down
- 1. a _____ reaction occurs when one or more substances are converted into new substance
- 3. anything that has mass and takes up space
- 5. type of reaction that involves oxygen and produces heat & light
- 6. used to speed up the rate of a reaction
- 8. 7 elements that will always have a subscript 2 if not in a compound
- 11. a substance dissolved in water
- 12. using chemical formulas to describe a chemical reaction
- 16. type of chemical equation that is not balanced
- 17. type of chemical reaction where 2 or more reactants combine to make 1 product