Ques:Answer the following question given this paragraph: At the top of the troposphere is a thin layer of air called the tropopause. You can see it in Figure above . This layer acts as a barrier. It prevents cool air in the troposphere from mixing with warm air in the stratosphere. Q: What thin layer of air acts as a barrier to prevent cool air from mixing with warm air in the stratosphere? Choices: - methosphere - endosphere - liposphere - tropopause A:

Ans:tropopause
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Ques:Answer the following question given this paragraph: Upwelling brings nutrients to the surface from the ocean floor. Nutrients are important resources for ocean life. However, they aren't the only resources on the ocean floor. Q: What process brings nutrients from the ocean's floor to its surface? Choices: - Down welling - coastal swell - Tides - upwelling A:

Ans:upwelling
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Ques:Answer the following question given this paragraph: Calcium fluoride is used to fluoridate drinking water to promote dental health. Crystalline CaF 2 (d = 3.1805 3. Q: What is used to fluoridate drinking water to promote dental health Choices: - carbon fluoride - calcium fluorine - carbon fluorine - calcium fluoride A:

Ans:calcium fluoride
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Ques:Answer the following question given this paragraph: The solubility of a substance is the amount of that substance that is required to form a saturated solution in a given amount of solvent at a specified temperature. Solubility is often measured as the grams of solute per 100 g of solvent. The solubility of sodium chloride in water is 36.0 g per 100 g water at 20C. The temperature must be specified because solubility varies with temperature. For gases, the pressure must also be specified. Solubility is specific for a particular solvent. We will consider solubility of material in water as solvent. Q: What term means the amount of a substance required to form a saturated solution in a given amount of solvent at a specified temperature? Choices: - viscosity - concentration - turbidity - solubility A:

Ans:
solubility
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