| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.37 |
| Score | 0% | 67% |
An element in the physical state of __________ maintains a constant volume and shape.
liquid |
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solid |
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gel |
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gas |
An element in a solid state has atoms or molecules that are constricted and do not move freely. Solids maintain a constant volume and shape and exist at a lower temperature than liquids or gases.
Which of the following is related to the Cambrian Explosion?
first civilizations |
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carbon dating |
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extinction of dinosaurs |
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fossil record |
The Cambrian period is one of the most significant geological time periods. Lasting about 53 million years, it marked a dramatic burst of changes in life on Earth known as the Cambrian Explosion. It is from this period that the majority of the history of life on Earth, as documented by fossils, is found. Called the fossil record, the layering of these mineralized imprints of organisms preserved in sedementary rock have allowed geologists to build a historical record of plant and animal life on Earth.
The hottest of Earth's atmospheric layers is which of the following?
mesosphere |
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thermosphere |
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troposphere |
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stratosphere |
Temperatures again increase with altitude in the thermosphere which is the hottest (4,530 °F / 2,500 °C) atmospheric layer due to direct exposure to the Sun's radiation. However, the gas in this layer is highly diluted so even though the atoms of gas may be very high in temperature, there are too few of them to effectively transfer much heat.
Which of the following is not a medium for sound waves?
liquid |
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none of these is a medium for sound waves |
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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.
Which of the following represents the largest value?
1 cL |
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1 ML |
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1 mL |
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1 kL |
Mega (M) is 106, kilo (k) is 103, centi (c) is 10-2, milli (m) is 10-3 so 1 ML represents the largest value.