Suppose a group of volunteers is planning on building a park
near a local lake. The lake is known to contain low levels of
arsenic (As). Therefore, prior to starting construction, the group
decides to measure the current level of arsenic in the lake.
a) If a 15.7 cm3 sample of lake water is found to have 164.5 ng
As, what is the concentration of arsenic in the sample in parts per
billion (ppb), assuming that the density of the...