Science Vocabulary 6

3. numbers that appear before a formula in a chemical equation to show the relative proportions of each reactant and product
4. new substances formed as a result of a chemical reaction
7. a chemical bond in which two atoms share a pair of valence electrons
8. the force that holds cations and anions together
10. the force that holds atoms or ions together as a unit
11. a mixture of two or more elements, at least one of which is a metal, that has the characteristic properties of a metal
14. a chemical reaction in which two compounds exchange positive ions and form new compounds
16. a neutral group of atoms that are joined together by one or more covalent bonds
17. an ion with a positive charge
18. a representation of a chemical reaction in which the reactants and products are expressed as formulas
19. a substance that undergoes change in a chemical reaction
20. a chemical reaction in which two or more substances react to form a single substance

1. a chemical reaction in which a compound breaks down into two or more simpler substances
2. a diagram of an atom, ion or molecule in which each dot represents a valence electron
5. notation that shows what elements a compound contains and the ratio of the atoms or ions of these elements in the compound
6. a chemical reaction in which one element takes the place of another element in a compound
9. the energy stored in chemical bonds
12. an ion with a negative charge
13. the attraction between a metal cation and the shared electrons that surround it
15. an atom or group of atoms that has a positive or negative charge