Vocabulary chapter 18 and 19

5. molecule that shares electrons equally and does not have opopositely charged ends
6. the mass in grams of one mole of a substance
8. in a chemical reaction, the new substance or substances formed
9. reaction in which two ionic compound in solution are combined, can produce a precipitate, water, or gas
11. a covalent bond in which electrons are shared equally by both atoms
12. chemical shorthand that uses symbols to tell what elements are in a compound and their ratios
13. SI unit for quantity equal to 6.022x10^23 units of that substance
15. chemical reaction in which one element replaces another element in a compound
19. the force of attraction between atoms when they share electrons
20. chemical reaction that requires thermal energy in order to proceed
22. shorthand method used to describe chemical reactions using chemical formulas and other symbols
23. number in a chemical equation that represents the number of units of each substance taking part in a chemical reaction

1. process in which one or more substances are changed into new substances
2. chemical equation with the same number of atoms of each element on both sides of the equation
3. a type of chemical reaction that occurs when a substanc reacts with oxygen to produce energy in the form of heat and light
4. chemical reaction in which one substance breaks down into two or more substances
7. a neutral particle that forms as a result of electron sharing among atoms
10. a neutral molecule in which unequal electron sharing results in a slightly positive end and slightly negative end
14. chemical reaction in which two or more substances combine to form a different substance
16. charged particle that has either more or fewer electons than protons
17. force that holds atoms together in a compound
18. chemical reaction in which energy is primarily given off in the form of thermal energy
21. in a chemical reaction, the substance that reacts