| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.95 |
| Score | 0% | 59% |
Which of these is matter than cannot be separated into different types of matter by ordinary chemical methods?
atom |
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compound |
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element |
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molecule |
An element is matter than cannot be separated into different types of matter by ordinary chemical methods.
Which of the following is not a medium for sound waves?
none of these is a medium for sound waves |
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liquid |
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vacuum |
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solid |
A vibrating object produces a sound wave that travels outwardly from the object through a medium (any liquid or solid matter). The vibration disturbs the particles in the surrounding medium, those particles disturb the particules next to them, and so on, as the sound propagates away from the vibration.
Water freezing or boiling is an example of which of the following?
phase transition |
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cooling |
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sublimation |
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heating |
A substance undergoes a phase transition when it moves from one state of matter to another, for example, when water freezes or boils.
Which is the proper order of Earth's atmospheric layers from the surface up to space?
mesosphere, thermosphere, stratosphere, troposphere |
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stratosphere, troposphere, mesosphere, thermosphere |
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troposphere, stratosphere, mesosphere, thermosphere |
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thermosphere, mesosphere, stratosphere, troposphere |
The troposphere is the closest layer to Earth, followed by the stratosphere, mesosphere, and finally the thermosphere which borders space.
Veins __________ blood at __________ pressure.
deoxygenated, low |
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oxygenated, low |
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oxygenated, high |
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deoxygenated, high |
Veins carry blood back to the heart from the body. While arteries are thick-walled because they carry oxygenated blood at high pressure, veins are comparatively thin-walled as they carry low-pressure deoxygenated blood. Like the heart, veins contain valves to prevent blood backflow.