1. A student analyzes soil samples from her backyard. She organizes the samples into three categories, based on their pH. The three categories are: pH less than 8, pH between 8 and 8.5, pH greater than 8.5. Which type of graph should she use to show the percent of samples in each group?

Stem and leaf plot
Circle graph
Line graph
Scatter plot
2. Which would be the most reliable source for information about the toxicity of an industrial chemical?

A webpage on the internet with no sources listed
A brochure by a company that produces the chemical
A scientific journal article that is peerreviewed
An opinion expressed by a chemistry professor