| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.07 |
| Score | 0% | 61% |
Which of these is a type of Earth's crust?
terrestrial |
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oceanic |
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sedimentary |
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metamorphic |
The crust is the Earth's outermost layer and is divided into oceanic and continental types. Oceanic crust is 3 miles (5 km) to 6 miles (10 km) thick and is composed primarily of denser rock. Continental crust is 20 to 30 miles (30 to 50 km) thick and composed primarily of less dense rock. The crust makes up approximately one percent of the Earth's total volume.
Which of the following is the narrowest classification of life?
genus |
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domain |
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species |
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family |
The narrowest classification of life, species, contains organisms that are so similar that they can only reproduce with others of the same species.
As part of digestion, the liver produces bile which breaks down:
protein |
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fat |
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sugars |
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starches |
The liver produces bile which emulsifies (separates) fat.
pH is a scale that measures of how basic or acidic a solution is. A solution with a pH of 4 is:
acidic |
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alkaline |
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neutral |
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basic |
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.
Meteoroids, meteors and meteorites are categorized based on which of the following?
their density |
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their location |
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their temperature |
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their size |
Smaller rocks shed by asteroids and comets are called meteoroids. When these rocks reach Earth's atmosphere, they burn up in the mesosphere and become meteors. If a meteor manages to reach the Earth, it is called a meteorite.