Ch. 6&7

5. a chemical reaction in which one element takes the place of another element in a compound
7. the energy stored in chemical bonds
10. the force that holds cations and anions together
11. numbers that appear before a formula in a chemical equation to show the relative proportions of each reactant and product
12. an atom or group of atoms that has a positive or negative charge
13. a mixture of two or more elements, at least one of which is a metal, that has the characteristic properties of a metal
15. new substances formed as a result of a chemical reaction
17. a chemical reaction in which two compounds exchange positive ions and form new compounds
18. a representation of a chemical reaction in which the reactants and products are expressed as formulas
19. an ion with negative charge
20. the force that holds atoms or ions together as a unit

1. a neutral group of atoms that are joined together by one or more covalent bonds
2. notation that shows what elements a compound contains and the ratio of the atoms or ions of these elements in the compound
3. an ion with a positive charge
4. a chemical bond in which two atoms share a pair of valence electrons
6. a diagram of an atom, ion or molecule in which each dot represents a valence electron
8. a chemical reaction in which a compound breaks down into two or more simpler substances
9. the attraction between a metal cation and the shared electrons that surround it
14. a chemical reaction in which two or more substances react to form a single substance
16. a substance that undergoes change in a chemical reaction