CHEM 107 SI Session Week 2 Day 1 (Chapter 1)
1. Determine whether each molecular diagram represents a pure substance or a mixture. If it
represents a pure substance, classify the substance as an element or a compound. If it represents a
mixture, classify the mixture as homogeneous or heterogeneous.
2. Classify each of the listed properties of ozone (a pollutant in the lower atmosphere but part of
a protective shield against UV light in the upper atmosphere) as physical or chemical.
a) bluish color
b) pungent odor
c) very reactive
d) decomposes on exposure to UV light
e) gas at room temperature.
3. Are the following changes chemical or physical? Explain.
