8a. A scientist did an experiment in 1642 to evaluate where a plant's mass came from. He grew a willow tree in a pot and added only water during the five-year experiment. At the beginning and
end of his experiment, he recorded the weight of the tree and the weight of the dried soil in the
pot. Complete this table to show the changes in weight for the tree and for the dried soil. (there
are 16 ounces in a pound)
Weight of Tree
Weight of Dried Soil
1642
5 pounds
200 pounds
1647
169 pounds, 3 ounces
199 pounds, 14 ounces
Change in Weight #
#
8b. The scientist concluded that almost none of the weight of the tree came from the dry soil, so
almost all of the weight of plants comes from water. Is his conclusion justified by the findings from
his experiment? Explain why or why not. If not, what would a valid conclusion be?