Earth and Space Science Study Guide
1. Define salinity
2. What is the name (or chemical formula) of the most abundant salt dissolved in
seawater?
3. Explain why the ocean is salty and why freshwater is fresh.
4. In what units do we typically express salinity?
5. If a solution is 20% salt, what is this in parts per thousand?
6. If 3g of salt are dissolved in a total of 1,000g of solution, what would the salinity be?
How would you express this salinity in percent?
7. If 3g of salt are dissolved in a total of 100g of solution, what would the salinity be?
How would you express this salinity in percent?
8. What is the typical range of seawater salinity in ppt? How would you express this
salinity in percent?
9. Does “brackish” water have a higher or lower salinity than typical seawater? What
about “hyper saline” water?
10. Freshwater coming into the oceans from rivers would tend to ________ the salinity of
seawater near the mouths of the rivers.
11. Two factors that slightly increase seawater salinity would be: (hint: one for polar
regions and one for low-latitude regions).
12. The density of seawater is _______ than the density of fresh water.
13. Explain why can Mr. Leque more easily float in the Great Salt Lake compared to
other lakes or even the sea?
14. Atoms are made up of _____, ______ and _______.
15. Three important types of bonds between atoms are _____, _____ and ______.
16. The type of bond formed between the hydrogen atoms with the oxygen atom in a
water molecule is a ________ bond.
17. Explain why water molecules are polar.
18. Describe at least one special property of water due to its being a polar molecule
19. Draw a water molecule using the following “ingredients:” Use: 10 protons, 10
neutrons and 10 electrons. (Show two electron orbitals (“shells”) for the oxygen atom
and one electron orbital for each hydrogen atom. Correctly show the approximate angle
between the hydrogen atoms).
20. Explain how you could determine the salinity of a water sample if you had access to
all of the materials we have in a typical science classroom.
21. Higher salinity causes ______ density; higher temperature causes _______ density.
(Choose “higher” and/or to “lower” fill in blanks)
22. In the open ocean, density is more controlled by _______. Near shore, density is more
controlled by ________. (Choose “salinity” and/or “temperature” to fill in blanks)
23. What is a thermocline?
24. What are three factors that affect the distribution of life in the oceans?
25. Photosynthesis can occur in the ______ zone. Below this zone is the _______ zone
where photosynthesis cannot occur.
26. Traveling away from shore you pass through the ______, ______ and _______ areas.
27. Production of organic mass from inorganic compounds via
chemosynthesis is called _________ __________.
photosynthesis or
28. T or F: When one organism consumes another, all of the energy is passed to the
consumer.
29. The approximate energy efficiency transfer between trophic levels is less than ______
percent.
Extra Credit: Describe in as much detail as you can the history of the Aral Sea (original
size, location, history/ reason for shrinkage