Across
- 4. Ions in two different compounds switch place: ___________ replacement
- 7. a reaction by which one or more substances change to produce one or more different substances
- 8. a group of atoms that are held together by chemical forces; a molecule is the smallest unit of matter that can exist by itself and retain all of a substance‘s chemical properties
- 9. an electron that is found in the outermost shell of an atom and that determines the atom’s chemical properties
- 13. the law of _________ of mass states the mass cannot be created or destroyed in ordinary chemical and physical changes
- 16. a representation of a chemical reaction that uses symbols to show the relationship between the reactants and the products
- 17. the law of __________ of energy states that energy cannot be created or destroyed but can be changed from one form to another
- 18. a bond formed by the attraction between positively charged metal ions and the electrons around them
- 19. a charged particle that forms when an atom or group of atoms gains or loses one or more electrons
- 20. a chemical reaction in which heat is released to the surroundings
Down
- 1. a chemical reaction that requires heat
- 2. a combination of chemical symbols and numbers to represent a substance: chemical _______
- 3. a substance or molecule that participates in a chemical reaction
- 4. A single compound breaks down into two (or more) simpler substances
- 5. a solid that is produced as a result of a chemical reaction in solution
- 6. Two (or more) substances combine to form a single compound
- 10. bond between oppositely charged ions, which form when electrons are
- 11. a substance that forms in a chemical reaction
- 12. the minimum amount of energy required to start a chemical reaction
- 14. One element takes the place of another element that is part of a compound: _____________ replacement
- 15. an interaction that holds atoms or ions together
- 17. a bond formed when atoms share one or more pairs of electrons