Salts in the Sea Lecture by Gillian Glegg

These flashcards cover key concepts from the lecture on salts in seawater, including major constituents, salinity measurement, and the behavior of elements within seawater.

What percentage of seawater is dissolved salt?

On average, 3.5% of seawater is dissolved salt.

What is salinity typically measured in?

Salinity is typically measured in practical salinity units (psu) which reflects the concentration of dissolved salts.

Name the major constituents of seawater.

The major constituents of seawater include Sodium (Na+), Chloride (Cl-), Sulfate (SO4^2-), Magnesium (Mg2+), and Calcium (Ca2+).

What are minor constituents found in seawater?

Minor constituents include trace elements like lithium and iodine.

What is the total approximate g/kg of salts in seawater?

The total approximate g/kg of salts in seawater is about 35 g/kg.

List the gases dissolved in seawater.

The gases dissolved in seawater include nitrogen, oxygen, carbon dioxide, and inert gases.

What role does evaporation play in determining salinity?

Evaporation originally determined salinity, leading to the use of parts per thousand in measurement.

What happens to the relative proportions of major ions in seawater despite changes in salinity?

The relative proportions of each major ion remain virtually constant regardless of changes in salinity.

How do heavy metals in seawater typically appear?

Heavy metals such as zinc, chromium, and cadmium are generally found in concentrations of the order of nanomolar (nM) or picomolar (pM).

What are conservative and non-conservative elements in seawater?

Conservative elements (e.g., Na, Mg) are unchanged by biological or chemical processes, while non-conservative elements (e.g., trace metals, nitrates) react with chemical or biological processes.