| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.96 |
| Score | 0% | 59% |
The asteroids in the Kuiper belt are composed of which of the following?
minerals |
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frozen methane, ammonia, and water |
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rock |
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gaseous methane, ammonia, and water |
The Kuiper Belt is similar to the asteroid belt but much larger. Extending beyond the orbit of Neptune, it contains objects composed mostly of frozen methane, ammonia, and water. Most notably, the Kuiper Belt is home to Pluto, a dwarf planet that, until a 2006 reclassification, was considered the ninth planet of the solar system.
pH is a scale that measures of how basic or acidic a solution is. A solution with a pH of 9 is:
alkaline |
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neutral |
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water |
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acidic |
An acid is a substance that gives up positively charged hydrogen ions (H+) when dissolved in water. A base (alkaline) gives up negatively charged hydroxide ions (OH-) when dissolved in water. pH is a scale that measures of how basic or acidic a solution is. Numbered from 0 to 14, solutions with a pH of 7 are neutral, less than 7 are acidic, more than 7 are alkaline.
Which of the following describes the Earth's mantle?
liquid |
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primarily solid |
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primarily liquid |
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solid |
Mantle makes up 84% of the Earth's volume and has an average thickness of approximately 1,800 miles (2,900 km). It is dense, hot, and primarily solid although in places it behaves more like a viscous fluid as the plates of the upper mantle and crust gradually "float" along its circumference.
Which of the following is the formula for power?
\(P = {\vec{w} \over t}\) |
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\(P = w t\) |
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\(P = {w \over t}\) |
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\(P = \vec{w}t\) |
Power is the rate at which work is performed or work per unit time: \(P = {w \over t}\) and is measured in watts (W).
Molecules and atoms that are outputs from a chemical reaction are known as which of the following?
reactants |
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products |
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results |
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side effects |
During a chemical reaction molecules and atoms (reactants) are rearranged into new combinations that result in new kinds of atoms or molecules (products).