The Oceans

Basics

Answer the following questions:

1) How much of the Earth's surface is covered by water?

3) What are hydrogen bonds?

a) Attractive forces between the strong positive regions on different water molecules.
b) Attractive forces between the slight negative regions on one water molecule and slight positive regions on another water molecule.
c) Attractive forces between the strong negative regions on different water molecules.
d) Repulsive forces between positive and negative regions on different water molecules.

5) How much more energy does it take to heat water by 1°C compared to air?

7) Suppose the Earth did not have so much water in the oceans, what would be the result?

a) Conditions would be much better for human life because the heat would be distributed more evenly.
b) Conditions would be harder, because of the low albedo of the oceans it would be hotter on Earth.
c) Conditions would be harder because temperatures would be either too hot or too cold.
d) Conditions would be the same as they are today.

9) What makes nutrients available to the biology in the oceans?

a) Oxygen and carbon dioxide dissolve in water and change their charged nature.
b) Nutrients and waste material dissolve in water and are destabilised.
c) A few substances dissolve in water and are stabilised by its charged nature.
d) Many ions and gases dissolve in water and are stabilised due to their charged nature.

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2) How much of the Earth's water is in the oceans?

4) What are the consequences of these hydrogen bonds?

a) Water has no hydrogen bonds.
b) Water is the only liquid which is stable at room temperature.
c) Water is liquid at room temperature unlike molecules of similar size.
d) Water can only exist as a liquid.

6) Which sentence describes the graphic above most correctly?

a) The structure of water (slight negative charge on the oxygen, slight positive charge on the hydrogen atoms) allows hydrogen bonds to form.
b) The structure of water (slight negative charge on the oxygen, slight positive charge on the hydrogen atoms) does not allow hydrogen bonds to form.
c) The structure of water (positive charge on the oxygen, negative charge on the hydrogen atoms) allows hydrogen bonds to form.
d) The structure of water (slight negative charge on the oxygen, slight positive charge on the hydrogen atoms) forms 5 chemical bonds.

8) Water has a high heat of vaporisation. What does this mean?

a) A lot of energy is needed to turn water vapour into liquid water.
b) A lot of energy is needed to turn liquid water into water vapour.
c) A lot of energy is needed to turn frozen water into liquid.
d) Little energy is needed to turn liquid water into water vapour.

10) What happens if more sodium chloride (salt) is added to water?

a) The formation of ice crystals becomes easier because salt already contains crystals.
b) The water becomes more dense and the freezing point gets lower.
c) The water molecules are repelled by the salt ions and the water gets less dense.
d) The salt content of the water remains the same.