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6. Which IS NOT a common mechanism for removal of the dissolved minor and trace elements from seawater?

  • Biological activity
  • Scavenging
  • Evaporation
  • Absorption

7. What is the approximate mass of sea salt that is dissolved in seawater?

  • 34 kilograms of sea salt for every 1 litre of seawater
  • 34 gram of sea salt for every 1L of sea water
  • 34 grams of sea salt for every 100 mL of seawater
  • 34 kilograms of sea salt for every 100 mL of seawater

8. Which of these statements is FALSE?

  • Only half the elements found in the periodic table are found dissolved in seawater
  • Dissolved oxygen display s non-conservative behaviour in seawater.
  • Profiles for scavenged elements show that their concentration decreases with depth.
  • The oldest bottom waters are in the North Pacific and so we should expect them to be most impoverished in dissolved oxygen

9. Which of the following statements is FALSE?

  • The major ions in seawater have a residence time longer than average ocean mixing time.
  • A constituent with an oceanic residence time of 100 years will be uniformly mixed throughout the oceans
  • That the chemical composition of the oceans is in steady state means that the rate of addition of dissolved constituents to seawater is balanced by their rate of removal, so that their concentrations do not change significantly with time.
  • The residence time of an element in seawater can be estimated by dividing its mass in the ocean by its annual input from rivers.

10. What is biological aggregation?

  • The formation of lots of small particles in a small space due to turbulence
  • The disturbance of organisms by particulate matter
  • The formation of large particles from smaller particles by activities such as zooplankton grazing
  • The attraction of organisms to a single location in the upper sunlit layers of the ocean

11. Which of the following is not found as a microscopic skeletal component of some sediments?

  • Pteropods
  • Clays
  • Foraminifera
  • Radiolaria

12. Which of the following statements is TRUE?

  • The majority of the dissolved constituents participate in repeated cycles of biological activity that removes elements from solution and returns them to solution many times before they end up in the sediment
  • Elements classified as recycled have concentration profiles resembling those of scavenged elements.
  • The deep oceans are poorly supplied with oxygen by the advection of deep water masses that were formed in the polar regions.
  • Variations in temperature affect the overall constancy of composition of seawater with respect to major constituents.