Exam Questions and CORRECT Answers
The Water molecule and basic atomic structure... what makes up the water molecule, the charges,
the bond angle? What's so peculiar about this molecule? - CORRECT ANSWER - two
small positive hydrogens (H+) and one negative oxygen (O-), bond angle of 105 degrees
MICKEY
The kinds of bonds in the water molecule? What do these bonds lead to? (important features of
water...) - CORRECT ANSWER - Covalent: sharing electrons between O and H;
Hydrogen: inter-molecule bonds bind water molecules together to form liquid; Bonds lead to
cohesion and surface tension
Polarity - why is water a polar molecule? What do we call water as a result and why? What
happens to salt (NaCl) in water? - CORRECT ANSWER - water is a polar molecule
because H has a partial + charge and attracts - and O has a partial - charge and attracts +;
As a result water is called H2O/universal solvent,
Salt dissolves in water
What are the 3 phases of water and how does one get changed to another? - CORRECT
ANSWER - solid, liquid, gas; remove heat= ice (solid), add heat= vapor (gas)
Thermal properties of water - what is the heat capacity of water? Why? What is that of sand and
why? What is the influence on coastal climates? - CORRECT ANSWER - High heat
capacity, oceans absorb/release large amounts of heat with little change in temp
Sand has low heat capacity, heats ups quickly and cools down quickly
Influence: light change in temp for water and lots of change with sand
How does Salinity and Temp affect Density? What is density? What happens to cold, salty
water? What happens to warm brackish water?... what does water do at the poles and why? What
happens at the Equator? - CORRECT ANSWER - Cold salty waters are more dense and
sink, warm brackish waters rise
, Cold water molecules get closer and contract and become more dense (poles)
Warm water molecules expand and become less dense (equator
What's the temp of the max density of water? How does the density of water change with
freezing? Why does ice float on water? - CORRECT ANSWER - 4 degrees C (1g/cm3)
Water gets less dense as it freezes, ice floats bc it's less dense than water
Salinity - what is it, and what is average salinity in the world's oceans? What are the most
abundant salt ions? - CORRECT ANSWER - Salinity: total amount of dissolved solids in
water
Average salinity is 35% in oceans
Most abundant salt ions are chloride and sodium
How does surface salinity change (from equator to subtropical latitudes to polar latitudes?...);
What are the evaporation latitudes and the precipitation latitudes?... Application: the salinity of
the Mediterranean, the history of the Mediterranean basin... salinity of the Baltic Sea -
CORRECT ANSWER - High/polar latitudes have low salinity (high precipitation, low
evaporation),
Subtropical latitudes have high salinity (low precipitation, high evaporation)
Equator has salinity in between (high precipitation and evaporation)
Mediterranean Sea has high salinity, dried up because of closed contact with Atlantic
Baltic Sea is brackish (in between salty and not) but you would still sink bc you're denser than
water
What are the most abundant sources of salts? - CORRECT ANSWER - Continental rocks-
rivers
Volcanic activity- brings things to
Hydrothermal vents- found in mid-ocean ridges
Density structure of a column of water: the surface layer, the thermocline, and the deep zone:
what are the salient characteristics of each? - CORRECT ANSWER - Surface Layer:
mixed layer, driven by winds, warmest (down to 200m, 2%)