14. a test tube containing 4.00 g of iron and 2.40 g of sulfur was
heated in a manner similar to that of the copper-and-sulfur
experiment. before heating, the total mass of the tube and con-
tents measured on the balance was 36.50 g. after heating, the
mass was measured again. the mass of the tube and contents
was 36.48 g.

a. do you think it reasonable that mass remained the same was
conserved during this experiment?

b. what additional steps would you take to increase your confi-
dence in your answer to part (a)?