Ask Jimmy and the Bug
art by Dean Stanton, text by Ellen Braaf
- What is one method of separating salt from water? How does this separate the salt and the water?
[anno: One method of separating salt from water is to boil the water. Boiling the water causes it to evaporate, and the salt is left behind.]
- Imagine you used this method to separate the salt from freshwater. How many pounds of freshwater would you have to treat to get one pound of salt? How many pounds of salt would you get if you used this method for 1,000 pounds of seawater? Answer both questions. Then write a statement comparing the amount of salt in seawater to the amount of salt in freshwater.
[anno: One thousand pounds of freshwater would have to be boiled to get one pound of salt. If 1,000 pounds of seawater were boiled, it would leave behind 35 pounds of salt. Seawater has 35 times as much salt as freshwater does.]
- Where does the salt found in seawater come from?
[anno: The salt found in seawater comes from rocks that have weathered and released minerals, from hydrothermal vents, and from underwater volcanoes.]
- What affects the concentration of salt in a body of water?
[anno: The concentration of salt in a body of water may be affected by the water's ability to flow both in and out. If water flows in and out of a body of water, such as a lake, the concentration of salt stays low. If water carrying salt flows into but not out of the body of water, then the concentration of salt will increase. Some water may escape by evaporation, but the salt will be left behind.]