Water
is so common to students that they can't see its special
properties, but water (without any additives) has
characteristics that make it unique. It has a high
boiling point, low freezing point, is tasteless, and
odorless.
The
density of a substance is the mass of that substance
compared to the volume that the substance occupies.
Density will vary depending upon the temperature. The
density of water as a liquid is higher than that of water
vapor. Other substances have other densities, in this lab
we want the students to compare the different densities of
certain liquids while comparing them to water. After the
students complete the density portion of the lab, they can
start thinking about the effects of oil pollution on
water. Oil will float and cause a problem for organisms
that live on the surface.
