Revision test 1 Flashcards
How saline is the ocean?
35g/l
Define the term density. Explain how it plays a role in the ocean.
The density of a substance is a mass unit per volume.
In percentage, seawater is a mixture of how much pure water and other material?
complex mixture of 96.5 percent water, 2.5 percent salts, and smaller amounts of other substances
What two factors influence the amount of dissolved gases in the water?
temperature and salinity
In relation to density, what is so unique about the properties of water that does not apply to other materials?
it is the ratio of 1
A person in water will become colder quicker than they would in air. Why is this?
Water conducts heat away from the body 25 times faster than air because it has a greater density (therefore a greater heat capacity).
What happens to sound underwater?
it moves faster than air because particles move better in denser materials
At what depth will light no longer become visible? Why does this occur?
As the light energy travels through the water, the molecules in the water scatter and absorb it. The aphotic zone exists in depths below 1,000 meters.
Define the term viscosity and use it to explain the properties of seawater.
The resistance of a liquid flowing though or a passing an object. Sea water viscosity increases in colder water
What is meant by the term buoyant?
how easily a substance floats
A diver is floating on the surface of the water, trying to descend. He is having troubles keeping himself down. Explain what is happening to the diver and what he can do to descend.
He is less dense than the water so he is buoyant and floats. If you exhale you are less buoyant because you have less air in your lungs keeping you afloat.
