Unique Nature of Pure Water
What is the temperature at which pure water freezes?
0°C
What two main substances make up seawater?
Water and dissolved salts
What is the main salt found in seawater?
Sodium chloride
What gas enters the ocean from the atmosphere and is part of the carbon cycle?
Carbon dioxide
Which zone receives the most light than the other zones?
Epipelagic
What is the temperature at which pure water boils?
100°C
What is the average salinity of ocean water?
About 35 parts per thousand
What is the approximate pH range of ocean water?
8.0 to 8.3
What process converts carbon dioxide into organic compounds such as glucose?
Photosynthesis
Which zone is at 1000m - 4000m?
Bathypelagic
What property allows water to stick to itself?
Cohesion
Is seawater more or less dense than pure water?
More dense
Is normal ocean water acidic, neutral, or alkaline?
Alkaline
About what percentage of yearly CO2 emissions enters the ocean?
About 30%
Which zone is home to sea pigs, basket stars, and sea spiders?
Abyssopelagic
Why does ice float on liquid water?
Ice is less dense than liquid water.
What happens to seawater density when salinity increases?
Density increases
What gas dissolves in seawater and affects its chemistry?
Carbon dioxide
What is ocean acidification?
The process in which ocean pH drops and the water becomes less alkaline.
Which zone is known as the twilight zone?
Mesopelagic
What type of bond causes water molecules to have many of their unique properties?
Hydrogen bonds
Why does seawater freeze at a lower temperature than pure water?
Salts lower its freezing point.
What chemical ions do marine organisms need to build and maintain shells?
Carbonate ions
Which organisms are especially at risk because they build shells or skeletons from calcium carbonate?
Organisms such as oysters and other shell-building marine animals.
Which zone is the Mariana Trench located in?
Hadalpelagic