Salinity
35 ppt
What two ions make up about 85% of the dissolved salts in seawater?
Sodium (Na) and Chloride (Cl)
What is the formula for calculating density?
Density = Mass/Volume
Which is more dense: freshwater or saltwater?
Which region has the lowest salinity: equator, subtropics, or polar regions?
Polar regions
What two processes of the water cycle most directly affect salinity?
Evaporation and precipitation
What are trace elements and why are they important?
What units are commonly used for mass and volume in density calculations?
Mass: grams (g) or kilograms (kg); Volume: mL, L, or cm3
How does salinity affect the density of seawater?
As salinity increases, density increases
Why do subtropical regions have the highest salinity?
Dry climate and high evaporation
What is the most common compound that makes up ocean salt?
Sodium chloride (NaCl)
Name two major elements found in seawater
chloride (Cl), sodium (Na), sulfate (SO₄²⁻), magnesium (Mg²⁺), calcium (Ca²⁺), and potassium (K⁺)
A cube has a mass of 10 g and a volume of 2 cm3. What is its density? Include units.
5g/cm3
How does temperature affect the density of seawater?
As temperature decreases, density increases
How does rainfall affect surface salinity?
Rainfall lowers surface salinity
How does evaporation affect salinity?
It increases salinity
What is the percentage of salt in fresh water
Less than 1% salt
How can you find the volume of an irregular object?
Using water displacement
Why does cold, salty water sink in the ocean?
It is denser than surrounding water
What seasonal change can cause surface salinity to increase? (season + water cycle)
Summer evaporation
Why does salinity increase slightly with depth in the oceans?
Less mixing and sinking of salty water from polar regions.
What is brackish water, and where might you find it in Rhode Island?
Water with 1-3% salt; found in Narragansett Bay
A rock displaces water from 50 mL to 77 mL. What is its volume?
How would the density of sea water be affected by polar ice melting?
Density would decrease due to added fresh water from melting ice, increasing the volume but keeping mass relatively the same.
How does latitude influence salinity patterns in the ocean?
Latitude affects climate, which controls evaporation and precipitation