Exam 2- OCEAN 100

What are the two features of an atom?

nucleus, electrons

What is 1?

Nucleus

What is 2?

Electrons

What makes up the nucleus?

Protons and Neutrons

What is an ion?

Atom electrically charged

What is a molecule?

Atoms held together by chemical bonds

What are the atoms of a water molecule? (name and amount)

1 oxygen and 2 hydrogen

What is the charge of oxygen?

Negative

What is the charge of hydrogen

Positive

How much electrons does oxygen have on its outer shell and how much does it want?

6 electrons

wants 8 (wants 2 more)

How much electrons does each hydrogen have on its outer shell and how much does it want?

Each have 1 electron

They both want 2 electrons (1 more each)

What is a covalent bond?

Sharing electrons between oxygen and hydrogen

Where do covalent bonds occur?

Inside one molecule

What are hydrogen bonds?

Inter-molecular bonds that connect water molecules together

What 2 important features of water does hydrogen bonds lead to?

Cohesion and Surface Tension

What is the bond angle of a water molecule?

105 degrees

What does it mean that H2O is a polar molecule?

The molecule has a slight positive charge on one end and a slight negative charge on the other end

What does the hydrogen end attract?

It attracts the negative charge of something else

What does the oxygen end attract?

It attracts the positive charge os something else

Why is water called the universal solvent?

The polarity of the water molecule allows water to dissolve just about anything, given enough time

What is Salt made of and what are the charges?

Sodium (+)

Chloride (-)

How does water dissolve salt?

Hydrogen takes away chloride

Oxygen takes away Sodium

When water evaporates, what does it leave behind? What is the result on land?

Salt

Salt can get encrusted on shores

What must you do to water to make it change phases?

Add heat energy or remove heat energy

What are the three phases of water?

• Ice (Solid)

• Water (Liquid)

• Vapour (Gas)

What do the bonds look like for the ice phase?

All molecules hydrogen bonded ans six-sided

What do the bonds look like for the water phase?

Most molecules are hydrogen bonded

What do the bonds look like for the vapour phase?

None of the molecules are hydrogen bonded

What is heat capacity?

The amount of heat required to raise temperature of 1gm of a substance by 1 degrees Celsius

What has the highest heat capacity of any substance?

Water

What does it mean that water has a high heat capacity?

It requires a lot of heat to change temperature

Does it take a short or long time for water to heat up?

A long time

Does water store and release a lot or only a small amount of heat?

A LOT

What is thermal inertia?

Because of hydrogen bonds, water takes a lot of heat energy to heat up

What moderates the climate?

Oceans

Does the ocean have extremes or is it relatively stable?

Relatively stable

What has a larger temperature range, ocean or land?

Land

When it is hot, why is the sand hot but not the ocean?

Because sand has a low heat capacity while ocean has a high heat capacity

What has a larger temperature range, land or ocean?

Land

How does temperature affect density?

As temperature decreases density increases

How does salinity affect density?

As salinity increases density increases

What happens to cold, salty water because of gravity?

It sinks

Where do cold salty waters sink?

At high latitudes (polar/ subpolar regions)

What is downwelling?

Water at surface sinks down

Where is a major cause of downwelling?

Weddell Sea, Antartica

Why is Weddell Sea a major cause of downwelling?

Major ice formation so water is always sinking

At what temperature is density the highest?

4 deg C

Why does ice float?

Because it is less dense

What happens to density once it is less than 4 degrees C?

Water becomes less dense

What temperature is freezing point?

0 degrees celsius

Why is ice less dense?

There is more space, molecules are farther apart, so there is less mass per same volume

What is salinity?

Total amount of dissolved solids (ions) in water

What is the average percentage of salinity of seawater?

35%

What are the most abundant ions in water? What is that combination called?

Chloride, sodium

combined is salt

At what degree latitude is the highest salinity?

At 30 degrees latitude

What sea has a high salinity?

Mediterranean Sea

Where is surface salinity highest? At which conditions of precipitation? Why?

Surface salinity is highest where precipitation is lowest since the rain dilutes salinity

What two things can dilute salinity on Earth?

Rain and Rivers

What is the salinity at high latitudes?

Low salinity

Why is the salinity low at high latitudes?

High precipitation, river runoff, low evaporation, melting iceburgs

What is the latitude of subtropical regions?

About 30 degrees latitudes

What is the salinity at subtropical latitudes?

High salinity

Why is there high salinity at subtropical latitudes?

High evaporation, low precipitation, low runoff

What is the salinity at the equator?

Salinity is in between

Why is the salinity at the equator in between?

High evaporation and high precipitation

Would you float or sink in the Baltic Sea and why?

Sink because the water is not salty

Would you float or sink in the Dead Sea and why?

Float because the water there is very salty

How long ago did the Mediterranean Sea dry up?

5 million years ago

How is it known that the Mediterranean Sea dried up?

Deep canyons and layers of solid rock salt found underneath

What was blocked from the Mediterranean Sea? What does it cause?

Entrance to the Atlantic, causes higher salinity

What is the latitude of the Mediterranean Sea?

35 degrees

What is the salinity of the Mediterranean Sea? (range)

38-39%

What are the three most abundant sources of salts/ions?

continental rocks, volcanic activity, hydrothermal vents

What is the removal mechanisms for ions?

subduction zones

What are the three density structure layers of the oceans? (in order)

1. Surface Layer

2. Thermocline

3. Deep Zone

What is the most dense layer of the ocean

Deep ocean

What is the least dense layer of the ocean?

Surface layer

What is the depth of the surface layer?

0-200 meters

What are the two features of the surface layer?

1. Mixed warm layer

2. Driven by surface motion (currents, waves)

What is the depth range of the thermocline layer?

200 m - 1,000 m

What is special about the temperature in the thermocline?

The temperature rapidly decreases with depth, the further the cooler

What is the depth range of the deep zone?

1,000 m - 4,000 m

How would you describe the water in deep zones (4 features)?

Dark, cold, salty, and dense waters

What is the exception of deep zone features?

Hydrothermal vents

In what waters do thermoclines exist?

Tropical and temperate waters

Where are thermoclines absent?

At the poles :3

Why is thermocline absent at the poles?

Because of downwelling where cold, salty waters are sinking

What is thermal expansion?

When the molecules are more spread apart because of warmer waters

What is thermal contraction?

When the waters are more condensed because of colder waters

What is the sound transmission of water?

Really fast

Does ice contract? Why or why not?

It does not contract because there is a lot of space between molecules

What is the finger of death?

Ice that is filled with so much salt that gravity pulls it down killing creatures on the sea floor