Across
- 3. bond formed when atoms share electrons
- 5. substances that form as a result of a reaction
- 6. substances that exist before the reaction begins
- 8. a reaction that releases heat energy
- 12. symbol with dots to show electron in outer energy level
- 14. large protein molecules that change the rate of a reaction in your body so that cells can work properly
- 16. a charged atom
- 17. the group of elements that have stable outer energy levels
- 18. bond in which electrons are shared unevenly
- 20. pure substance containing two or more elements that are bonded
- 22. energy needed to start a reaction
- 23. chemical symbols and numbers that shows type and how many of each element are present
Down
- 1. bonds when metal atoms share pooled electrons
- 2. how fast a reaction occurs
- 3. a process that produces a new substance
- 4. a reaction that absorbs heat energy
- 7. a polar covalent molecule with two hydrogen atoms, one oxygen atom
- 9. force that holds two atoms together
- 10. tells chemists the reactants, products, physical state, and proportions of each substance present
- 11. shows the number of atoms of an element present in a compound
- 13. the law that states: in a closed system, mass of reactants must equal the mass of product
- 15. amount of substance present in a certain volume
- 16. bond formed by two charged atoms (usually a metal and a nonmetal)
- 19. type of change that produces a new substance
- 21. neutral particle formed when atoms share electrons