| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.33 |
| Score | 0% | 67% |
Which of the following is not a medium for sound waves?
none of these is a medium for sound waves |
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vacuum |
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liquid |
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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.
The rows of the Periodic Table of the Elements are called:
groups |
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families |
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periods |
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shells |
The rows of the Periodic Table are called periods and contain elements that have the same number of electron shells ordered from lower to higher atomic number.
When compared to eukaryotic cells, prokaryotic cells are:
more complex |
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less complex |
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similarly complex |
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none of these |
Cells are classified into one of two groups based on whether or not they have a nucleus. Eukaryotic cells have a nucleus, prokaryotic cells do not have a nucleus and therefore have a less complex structure than eukaryotic cells.
Which of the following is not a method of heat transfer?
radiation |
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convection |
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reflection |
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conduction |
Heat is always transferred from warmer to cooler environments through conduction, convection, or radiation.
The rate of vibration of sound is called:
volume |
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amplitude |
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frequency |
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period |
The rate of vibration of sound is called frequency and is measured in hertz (Hz). One hertz is one repetition per second and sounds with high frequency have a higher pitch than sounds with lower frequency. Humans can hear sounds in the range of 20 Hz to 20 kHz.