💧 Water Molecules
What is the chemical formula for water?
H₂O
What are the three phases of water
solid liquid gas
What is the formula for density?
Density = mass ÷ volume.
What is the concentration of dissolved salts in water called?
Salinity
What term means a measure of water clarity?
Turbidity
How many hydrogen atoms are in one water molecule?
2
What happens to water molecules when they are heated?
They speed up
What two factors determine the density of ocean water?
temperature and salinity
What unit is used to measure salinity?
ppt (parts per thousand)
Which generally has higher turbidity: coastal water or open-ocean water?
Coastal water
How many oxygen atoms are in three molecules of water?
3
At what temperature does freshwater freeze?
0°C (32°F).
Which is denser: freshwater or saltwater?
saltwater
What is the average salinity of the ocean?
35 ppt
What ocean layer experiences a rapid decrease in temperature?
A thermocline
What type of bond holds the hydrogen and oxygen atoms together within a water molecule?
covalent bond
At approximately what temperature does salty water freeze?
Answer: −1.8°C.
Which is denser: cold water or warm water?
cold water
What instrument is used to measure salinity in a water sample?
A refractometer
Why do tropical oceans generally have higher salinity?
increased evaporation
What causes one H₂O molecule to be attracted to another H₂O molecule?
A hydrogen bond.
How does warmer temperature affect the rate of evaporation?
Answer: Water evaporates faster at warmer temperatures.
You place salty water and freshwater together. Which one will sink below the other, and why?
Saltwater sinks below freshwater because saltwater is denser
Name three freshwater inputs that decrease ocean salinity.
Rainfall, melting ice, and runoff from land
Why is oxygen highest near the ocean's surface?
Sunlight allows more photosynthesis, which produces more oxygen.