Unit 2 Earth's Water

_{Bryan is doing a science experiment on the stomata of plants. Bryan has a tomato plant. He uses wax to cover all the stomata on the leaves of the plant. After five days, Bryan observes that the plant is wilting. What is the best explanation for Bryan’s observation?}

• The plant released too much water into the air.
• The plant was unable to carry out transpiration.
•  Condensation could not occur on the leaves of the plant.
• The plant was unable to take in water through its leaves.

Bryan is doing a science experiment on the stomata of plants. He wants to study how tomato plants are involved in the water cycle. What is the main role of plants in the water cycle?

• They take in water from the air.
• They release water vapor into the air.
• They provide a surface for condensation.
• They store water in their stems and leaves.

As water changes state, the water either absorbs or releases energy. Which of these answers is a process that releases energy?

• ice subliming
• snow melting
• lake water freezing
• ocean water evaporating

Which process changes water into a gaseous state?

• deposition
• sublimation
• precipitation
• condensation

If a warm wind passes over snow, the snow can be heated rapidly. When this happens, the snow can change directly into water vapor without first becoming liquid water. What is the correct term for this process?

• melting
• deposition
• sublimation
• evaporation

What word describes when water is attracted to other substances?

• cohesion
• adhesion
• capillary action
• surface tension

The attraction that causes water and other liquids to form drops on thin films is called ________________. This is also water’s ability to be attraction to other water molecules.

• adhesion
• capillary action
• cohesion
• surface tension

Water is polar because...

• The unequal sharing of electrons gives the water molecule a slight negative charge near its oxygen atom and a slight positive charge near its hydrogen atoms.
• The molecule has two poles, at which the it is colder than other regions of the molecule.
• The unequal sharing of electrons gives the water molecule a slight negative charge near its hydrogen atoms and a slight positive charge near its oxygen atom.
• The water molecule is neutral.

Why does ice float?

• As water freezes, it expands and its density decreases.
• As water freezes, it takes up more hydrogen from the atmosphere, causing it to have a greater buoyancy.
• As water freezes, air becomes trapped between the hydrogen bonds of water molecules.
• As water freezes, it takes up more oxygen from the atmosphere, causing it to have a greater buoyancy.

A molecule with electrically charged areas is called a _______________.

• magnet
• polar molecule
• solution
• electrical molecule