| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.35 |
| Score | 0% | 67% |
Absolute zero is which of the following?
the freezing point of oxygen |
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0°C |
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the freezing point of hydrogen |
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the coldest temperature possible in the universe |
In contrast to the Celsius scale (measured in degrees centigrade) that fixes 0° at the freezing point of water and the Fahrenheit scale that uses 32°, the Kelvin scale fixes 0 at absolute zero (-273°C) which is the lowest temperature possible in the universe.
The process of diffusion allows __________ to exchange oxygen, carbon dioxide, nutrients, and waste between blood and the body's cells.
veins |
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arteries |
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red blood cells |
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capillaries |
Capillaries are small thin-walled vessels that permit the exchange of oxygen, carbon dioxide, nutrients, and waste between blood and the body's cells. This process of exchange is called diffusion.
Which of the following is the smallest component of an element that still retains the properties of the element?
molecule |
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neutron |
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atom |
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element |
An atom is the smallest component of an element that still retains the properties of the element.
What is a major difference between the somatic and autonomic nervous systems?
one is inherited, the other is learned |
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each belongs to a different nervous system |
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one controls voluntary activity, one controls involuntary activity |
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one controls thinking, the other controls feeling |
Both are part of the peripheral nervous system. The somatic nervous system sends sensory information to the central nervous system and controls voluntary actions while the autonomic nervous system regulates involuntary activity in the heart, stomach, and intestines.
The Sun is a __________-type main-sequence star.
S |
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E |
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G |
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D |
The Sun is a G-type main-sequence star (G2V) but is informally known as a yellow dwarf star. Composed of 73% hydrogen and 25% helium, the hot plasma that makes up the Sun reaches 9,900°F (5,505°C) at the surface. It formed approximately 4.6 billion years ago and makes up 99.86% of the mass in the solar system.