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Unit 2: Systems at Sea

Total questions: 52

Worksheet time: 28mins

Name
Class
Date
1.

Match each molecular formula to its correct composition.

a)

Two hydrogen atoms and one oxygen atom

1.

H2O

b)

One hydrogen atom and two oxygen atoms

2.

HO2

c)

Two hydrogen atoms and two oxygen atoms

3.

H2O2

d)

One oxygen atom and one hydrogen atom

4.

HO

2.

What mass of salt (in grams) is required to prepare a solution with a concentration of 35 ppt using 150 ml of water?

a)

5.25 g

b)

0.525 g

c)

52.5 g

d)

0.0525 g

3.

What is the typical pH level of seawater under normal conditions?

a)

7.5-7.8

b)

8.1-8.2

c)

8.4-8.6

d)

7.9-8.0

4.

What effect does evaporation have on the concentration of salt in seawater?

a)

Evaporation reduces the concentration of salt

b)

Evaporation increases the concentration of salt

c)

Evaporation does not change the concentration of salt

d)

Evaporation balances the concentration of salt

5.

During a marine biology class, Scarlett and Aiden were discussing ocean layers. They learned that the area where salinity changes significantly with depth is called the

a)

Thermocline

b)

Pycnocline

c)

Halocline

d)

Incline

6.

How do water molecules behave as they approach the freezing point?

a)

They move faster and disperse

b)

They form a rigid lattice structure

c)

They become gaseous

d)

They dissolve into other substances

7.

What happens to the concentration of dissolved oxygen as you go deeper into the ocean?

a)

It increases

b)

It decreases

c)

It stays the same

d)

It varies unpredictably

8.

At what depth is the oxygen minimum zone most commonly located?

a)

150m

b)

250m

c)

500m

d)

450m

9.

Where is ocean water most likely to be the coldest?

a)

Near the equator

b)

At the mid-latitude zones

c)

Near the water's surface

d)

Near the poles

10.

What is the primary factor affecting the stratification of ocean water layers?

a)

Salinity

b)

Mass

c)

Temperature

d)

Pressure

11.

Match the following seawater salinity levels with their typical values.

a)

32 ppt

1.

Salinity of brackish seawater

b)

34 ppt

2.

Salinity of the Red Sea

c)

35 ppt

3.

Average salinity of ocean water

d)

36 ppt

4.

Salinity of the Mediterranean Sea

12.

During a geography class, Samuel and Charlotte were discussing the density of different bodies of water. Which of the following bodies of water is the most dense (assuming the temperature of each is the same)?

a)

Red Sea 42 ppt

b)

Atlantic Ocean 33 ppt

c)

Gulf of Mexico 16 ppt

d)

Mobile Bay 9 ppt

13.

What is the name of a natural underground reservoir where freshwater and saltwater meet, creating a visible halocline?

a)

Thermocline

b)

Blue Hole

c)

Lagoon

d)

Cenote

14.

Which color of light penetrates the ocean the furthest?

a)

Blue

b)

Green

c)

Red

d)

Violet

15.

During the rainbow lab, we observed the effect of salinity on water density. Based on the lab results, what can be concluded about the relationship between salinity and water density?

a)

Higher salinity results in lower water density.

b)

Salinity does not alter the density of water.

c)

Increased salinity leads to higher water density.

d)

Salinity causes water to freeze at a higher temperature.

16.

Which bond connects water molecules?

a)

Hydrogen Bond connects hydrogen atoms.

b)

Covalent Bond connects oxygen atoms.

c)

Hydrogen Bond connects water molecules.

d)

Covalent Bond connects water molecules.

17.

An ocean is a large body of salt water. Ocean water is made up of:

a)

water and sand

b)

gases, water, and dissolved solids

c)

salt, sand, and water

18.

Which elements (besides hydrogen and oxygen) are most abundant in the oceans?

a)

Sodium and Chlorine

b)

Magnesium and Chlorine

c)

Sodium and Sulfur

d)

Sulfer and Calcium

19.
Temperature  increases
a)
Density increases
b)
Density decreases
20.
As salinity  increases
a)
Density increases
b)
Density decreases
21.
Ocean depth  increases & Salinity  increases then
a)
Temperature decreases because cold water is more dense and sinks
b)
Temperature increases because cold water is more dense and sinks
22.
When an object or substance is warmer, its particles move faster and get further apart (Tip for remembering: they are warmer and want to get cooler by moving away from one another)  True or False
a)
True
b)
False
23.
True or False Salinity increases as ocean depth increases.
a)
True
b)
False
24.

What color of light is absorbed closest to the ocean surface? (not able to be seen below 10 meters)

a)

Blue

b)

Red

c)

Green

d)

Yellow

25.

In this model, what is the order of layers from most dense to least dense?

a)

Blue, green, yellow, red

b)

Blue, yellow, green, red

c)

Green, Blue, yellow, red

d)

Red, yellow, green, blue

26.
Which process does NOT lead to a decrease in the salinity of water?
a)
runoff from land
b)
precipitation
c)
sea ice melting
d)
evaporation
27.

This zone of the ocean gets the most sunlight, so it has the most plants that need to undergo photosynthesis.

a)

Surface Zone

b)

Transition Zone

c)

Deep Zone

28.

Nora, Anika, and Scarlett are conducting an experiment for their science project. They learned that if human activities continue as they are, the ocean is predicted to become more

a)

acidic

b)

basic

c)

neutral

d)

ionic

29.

Carbonic acid makes oceans more​ (a)   which makes it ​ (b)   for shelled sea creatures to make​ (c)   food

Choose from the below words
acidic
basic
neutral
easier
harder
shells
food
friends
babies
30.

Imagine Daniel, Aria, and Maya are conducting a science experiment on ocean water. If they continue to add carbon dioxide to the water at the same rate, what is the predicted change in the ocean's acidity?

a)

More acidic

b)

More basic

c)

Neutral

d)

Ionic

31.

During a school trip to the aquarium, Evelyn, James, and Mason were discussing the impact of ocean acidification. They wondered which organism is most affected by this phenomenon. Can you help them?

a)

Sharks

b)

Coral reefs

c)

Jellyfish

d)

Seahorses

32.

What does the blue line show?

a)

CO2 in the water

b)

Air temperature

c)

Carbon emissions

d)

pH of the water

33.

What does the orange line show?

a)

CO2 in the water

b)

Air temperature

c)

Carbon emissions

d)

pH of the water

34.

What was the pH around 1989?

a)

about 8.1

b)

about 7.5

c)

about 8.5

d)

about 8.9

35.

What burns that creates ocean acidification?

a)

rocks

b)

plants

c)

fossil fuels

d)

coal

36.

What do some marine creatures do with the carbonate ion?

a)

use it as a food source

b)

use it as a defense mechanism

c)

use it to build shells and exoskeletons

d)

use it to cool body temperatures

37.

Bacteria fix nitrogen from the atmosphere into a form plants can use.

a)

True

b)

False

38.
Organisms that break down dead plants & animals and release nitrogen back into atmosphere...
a)
bacteria
b)
plants
c)
animals
d)
producers
39.
Plants and animals cannot use nitrogen directly from the air.
a)
True
b)
False
40.
What happens when organisms die and decay? 
a)
Their bodies are lifted up
b)
Their nitrogen returns to the soil
c)
they keep their nitrogen
d)
They stay on earth forever
41.

What happens when too much Nitrogen finds its way to the ocean?

a)

Algae Bloom

b)

Acid Precipitation

c)

Nitrogen Fixation

d)

Decomposition

42.
The amount of salt found in water is -
a)
temperature
b)
salinity
c)
pollution
d)
clarity
43.
As Density  increases
a)
Temperature decreases
b)
Temperature increases
44.
Temperature  increases
a)
Density increases
b)
Density decreases
45.
As salinity  increases
a)
Density increases
b)
Density decreases
46.
When an object or substance is cooler, its particles move slower and are closer together True Or False
a)
True
b)
False
47.

Hypoxia is...

a)

An increase in dissolved oxygen

b)

A decrease in dissolved oxygen

c)

An increase in density

d)

A decrease in density

48.

Which zone is known as the lit zone where light easily penetrates?

a)

photic zone

b)

aphotic zone

49.

Which is absorbed at greater depths?

a)

red and yellow visible light

b)

blue and green visible light

50.

What is seawater's thermocline influenced by?

a)

temperature

b)

salinity

c)

density

51.

Density ________ with increasing depth.

a)

increases

b)

decreases

c)

stays the same

52.

What are the two factors that influence density?

a)

temperature and salinity

b)

temperature and depth

c)

salinity and latitude

d)

temperature and latitude