You are comparing the surface tension on two bodies of water: a fresh-water pond and a salt-water lagoon. Which one, if measured, would have a higher surface tension?
a. the fresh-water pond because it has a lower density
b. the salt-water pond because it has a higher density
c. the fresh-water pond because it has a lower
d. the salt-water pond because it has a higher pH
The correct answer is a. the fresh-water pond because it has a lower density. Surface tension is caused by the cohesive forces between molecules at the surface of a liquid. The density of the liquid affects the strength of these cohesive forces, with lower density liquids having stronger cohesive forces and therefore higher surface tension. Freshwater has a lower density compared to saltwater, so the surface tension of a freshwater pond would be higher.
