Final answer:
The lowest concentration of dissolved oxygen in a sun-heated lake during the summer is typically at the bottom of the lake, as warm surface water holds less oxygen and doesn't mix well with the cooler, oxygen-poor deep water.
Thus the corret opction is:d
Step-by-step explanation:
The question pertains to where the lowest concentration of dissolved oxygen is likely to be found in a sun-heated lake during the summer.
The correct answer is d. at the bottom of the lake.
This phenomenon is due to the fact that warmer water can hold less dissolved oxygen, and in the summer, lakes can become stratified, with warmer, less-dense water on the top and cooler, denser, oxygen-poor water at the bottom.
Additionally, the process of decomposition by organisms at the lake's bottom consumes oxygen, leading to lower concentrations there.
The warm surface water doesn't mix well with the cooler deep water, leading to these stratified layers with varying levels of oxygen.
The complete question is:content loaded
In the summer, a sun-heated lake will tend to have the lowest concentration of dissolved oxygen
a. at the lake's surface.
b. about 2 m below the lake's surface.
c. at about the middle depth of the lake.
d. at the bottom of the lake.