Ocean salinity is generally well-mixed across regions and depth, compared to water on land. 

This test is closed book and closed notes (including physical copies of your cheat sheet) and must be your sole, individual work.Answer each question with a single answer unless otherwise stated.Click on the pdf file below the periodic table in order to view your cheat sheet.

What is a cause for elements that are not well mixed in the oceans (Choose all that apply): 

The solubility of gases into water increases with increasing temperature.

Particles and dissolved compounds in river water come from: Choose all that apply 

Why is liquid water considered a requirement for life? Choose all that apply 

Explain how the unusual density of ice has influenced Earths climate. 

Which exposure measurement method is most vulnerable to recall bias?

From which group should cases ideally be selected?

Why can’t cross-sectional studies determine cause-and-effect relationships?