4. For each balanced reaction, indicate the total number of atoms in the table below.

12. complete each of the following word equations for synthesis reactions. a. sodium + oxygen -> b. magnesium + fluorine -> 13. complete and balance the equations for the decomposition reactions. a. hgo -> [with the triangle heat symbol above the arrow] b. h2o(l) -> [with "electricity" written above the arrow]

Nonpoint source pollution is difficult to control because it

8.98 dm3 of hydrogen gas is collected at 38.8 °c. find the volume the gas will occupy at -39.9 °c if the pressure remains constant.