About 3% of the water on Earth is freshwater. Only about 40% of that freshwater is available for human use. Why is so much freshwater unavailable for human use?

• Its polluted
• Its saltwater
• Its frozen
• Its being guarded by dragons

Considering the properties of saltwater and freshwater, which statement is true?

• Freshwater is more dense
• Saltwater is less dense
• Objects are more buoyant when floating in Freshwater
• Objects are more buoyant when floating in Saltwater

Water's ___________ makes it an excellent solvent for salts, like sodium chloride, as well as other substances required by cells to carry out metabolic processes

• pH level
• Polarity
• Heat capacity
• Molecular weight

A straw bale barrier is shown in the picture. It lines the perimeter of the home construction site. The barrier traps sediment like soil and grass that might be lost and still allows water to escape. 
The straw barrier protects against ____________

• Theft
• Erosion
• Traffic
• Weathering

A group of Hazelwood North Middle students on a field trip found loose rock and gravel at the foot of a rocky cliff. These rocks were of the same material as the rocks on the cliff. The students know that the place has a cold and wet climate. On the basis of this evidence, what could be a possible explanation for the presence of the loose rock and gravel at the foot of the cliff?

• The rocks might have broken off due to alternating cycles of freezing and thawing of water.
• Oxygen in the air could have reacted with the minerals in the rock, causing the rusting of the rocks.
• The rocks were probably always there. Weathering cannot be the cause, because it possible only in warm and wet conditions.
• Weathering cannot affect rocks

 What could people do to DECREASE erosion of the Earth’s surface?

• Cut down more trees
• Allow natural vegetation to grow
• Allow cattle to graze more often
• Turn land into farms

Which process causes hillsides and mountains to gradually get smaller?

• Erosion
• Earthquake
• Tidal Waves
• Landslides

The earth is in a constant state of motion which creates forces that change the face of the Earth. Weathering is the force that breaks down rocks and other objects in nature into smaller pieces and erosion is the movement of the pieces that were broken off through the weathering process.
How do coastal plants prevent shoreline erosion?

• by absorbing water
•  by preventing rain
• by photosynthesis
• by holding soil in place with their roots

Water on Earth is either freshwater or saltwater. What is the percent ratio of freshwater to percent saltwater on Earth?

• 50% Freshwater, 50% Saltwater
• 90% Freshwater, 10% Saltwater
• 26% Freshwater, 74% Saltwater
• 3% Freshwater, 97% Saltwater

Mariah decided to put a glass of water into the freezer, as she thought it would cool the water more quickly than the refrigerator. Mariah began to watch TV and forgot about the water for many hours. When she finally remembered, she was surprised to see that the glass had shattered in the freezer. Which of these best describes why this occurred?

• Mariah must have accidently dropped the glass into the freezer and broke it
• The glass could not withstand the cold temperature of the freezer
• Water expands when it freezes which caused the glass to break
• Something in the freezer must have fallen on the glass and broke it