STUDY GUIDE Chapter 3 Castro & Huber
Recommendations to follow:
1.
Answers are thought to be short in most of the cases
2.
Try as much as you can to connect the terms and understand the association between some of the concepts, to get
the whole picture about the topic. Memorizing alone can give you probably around a 70/100 in the exam, , but some
questions always require connecting two or more ideas to come up with a short and precise answer.
3.
If you know most of these review questions you should do fine in the test, questions in the test will be variations of
the same themes covered in these questions.
Chapter 3
Nature of water
1. Differentiate between atoms, elements, and molecules
2. Explain the basic structure of the atom:
a) Types of particles
b) Particles that have a charge (positive or negative)
c) Particles that have a mass (weight)
d) What particles make up the nucleus of an atom?
e) What particles participate in the formation of molecules?
3. Why are the outermost electrons of an atom important? In other words, why do atoms make molecules?
4. Explain the difference between the two types of chemical bonds that hold atoms together to make molecules
(ionic and covalent)
5. Which type of chemical bond is responsible for the formation of carbs, lipids, proteins, etc.?
6. What is an ion? If you have Fe++, what does this mean for the structure of the atom? If you have Cl-?
7. Sketch molecule of water. What type of chemical bond keeps the atoms in water molecule together?
8. What type of bond keeps water molecules together? Explain polarity and how this determines the appearance
of the bond you just mentioned.
9. As water cools, density (mass/ volume) of water increases, but ice floats on top of water in regions that freeze
during winter. Explain why this happens and how this is important for living things.
10. Explain how hydrogen bonds change the heat capacity for the water and why this is important for marine
organisms
Salinity
11. What is the general effect of dissolved solids and, salts in particular, on the composition of water?
12. Give a definition for salinity. What ions (atoms) account for about 85% of the salt composition in seawater?
How are ions added to the water in the oceans? (picture in slide of saltwater composition)
13. What natural processes can change the salinity in the oceans?
Marine Biology
Instructor: Jose Bava, Ph.D
STUDY GUIDE Chapter 3 Castro & Huber
Effects of temperature and salinity on density
14. Salinity and temperature characterize the density of seawater, if we know two of these factors, the third one
can be determined using a TDS (temperature-salinity-density) diagram, no matter where in ocean you are
located. Which factor (temperature or salinity) changes the most in the oceans and hence is more important in
determining changes in density of the water?
15. What is the result on the density if temperature decreases? What is the result on the density if salinity
increases?
16. What methods can be used for water sampling and to determine factors like temperature, depth, salinity, etc.?
Dissolved oxygen and pressure
17. How different is the amount of dissolved oxygen in water compared to that of air?
18. Oxygen and gases in general, dissolved better in cold or warm water?
19. What regions of the world would you expect then to have more dissolved oxygen?
20. Solubility of gases changes with depth; an increase in depth is associated to colder waters, pressure also
increases and that favors oxygen solubility. In what part of the water column would you expect to have more
dissolved oxygen?
21. What is the rate of pressure change with depth?
22. What impact do drastic changes of pressure have on marine organisms?
Marine Biology
Instructor: Jose Bava, Ph.D