p. 180, #1-12

1. The law of conservation of matter is the statement that matter can neither be destroyed nor created.

2. A scientific law summarizes what has been learned my observation of nature.

3. These expressions are misleading because according to the law of conservation of matter, matter can not be disposed of by "throwing it away" and can not disappear by being "used up". Molecules can only be changed and decomposed, however this does not apply to atoms. Atoms are indestructible.

4.
a. Unbalanced
b. Unbalanced
c. Balanced

5.
a. 3
b. 2
c. 1

6.  See paper
a. 1, 3, 1, 3
b. 2, 3, 2, 2
c. 2, 3, 2

7.
a. 1, 3, 2, 2
b. 2, 25, 16, 18

8.
a. Yes.
b. No. Instead of changing the coefficients when balancing the equation, he changed the subscripts.
c. 1 Na2SO4 + 2KCL --> 2 NaCl + 1 K2SO4

9. It would take 400,000 seconds

10.
a. 32g
b. 48g
c. 100g
d. 58g
e.180g

11. Although copper and sodium have different masses, volumes, and densities, they have the same weight of each atom per mol.

12.
a. one atom
b. .5 atoms
c. .1 atoms
d. .03 atoms