| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.05 |
| Score | 0% | 61% |
Earth's breathable air is held in which atmospheric layer?
mesosphere |
|
troposphere |
|
stratosphere |
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thermosphere |
The Earth's atmosphere has several layers starting with the troposphere which is closest in proximity to the surface. Containing most of the Earth's breathable air (oxygen and nitrogen), it's a region with warmer temperatures closer to the surface and cooler temperatures farther away which results in the rising and falling air that generates weather.
Atoms of an element whose atoms can vary in the number of neutrons in their nucleus are called which of the following?
reactants |
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products |
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isotopes |
|
ions |
The atomic mass of an element listed in the Periodic Table represents the average mass of a single atom of that element and is measured in atomic mass units (amu). This number is an average as some elements have isotopes with atoms that vary in their number of neturons and, therefore, differ in weight.
-40°F is how many °C?
-8 |
|
\({40 \over 9}\) |
|
\(-{40 \over 9}\) |
|
-40 |
The formula to convert from F° to C° is:
\(C° = {5 \over 9} (F° - 32)\)
plugging in our values gives:
\(C° = {5 \over 9} (-40 - 32)\)
\(C° = {5 \over 9} (-72) = {{-72 \times 5} \over 9}\)
\(C° = {-360 \over 9}\)
\(C° = -40\)
In the classification of life, which of the following is not a kingdom?
plants |
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fungi |
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animals |
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bacteria |
Below domain, life is classified into six kingdoms: plants, animals, archaebacteria, eubacteria, and fungi. The last kingdom, protists, include all microscopic organisms that are not bacteria, animals, plants or fungi. (Archaebacteria and eubacteria are sometimes combined into a single kingdom, monera.)
The pitch of the siren of an approaching ambulance changes as it approaches you. This is an example of which of the following?
refraction |
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Doppler effect |
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sound radiation |
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reflection |
The Doppler effect occurs when the source or listener (or both) of sound waves is moving. If they're moving closer together, the listener perceives the sound with a higher pitch and, when they're moving apart, the listener perceives the sound with a lower pitch.