Your Results | Global Average | |
---|---|---|
Questions | 5 | 5 |
Correct | 0 | 3.29 |
Score | 0% | 66% |
Which of these is not a component of blood?
red blood cells |
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white blood cells |
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marrow |
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plasma |
Blood is created in bone marrow and is made up of cells suspended in liquid plasma. Red blood cells carry oxygen, white blood cells fight infection, and platelets are cell fragments that allow blood to clot.
The rate of vibration of sound is called:
period |
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frequency |
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amplitude |
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volume |
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.
Elements that belong to the same period in the Periodic Table of the Elements have the same number of:
atomic mass units |
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electrons |
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electron shells |
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protons |
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.
The crust and lithosphere of the Earth is made up of which of the following?
sedimentary rock |
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continents |
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metamorphic rock |
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plates |
The crust and the rigid lithosphere (upper mantle) is made up approximately thirty separate plates. These plates more very slowly on the slightly more liquid mantle (asthenosphere) beneath them. This movement has resulted in continental drift which is the gradual movement of land masses across Earth's surface. Continental drift is a very slow process, occurring over hundreds of millions of years.
Which of the following describes the Earth's mantle?
primarily liquid |
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solid |
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primarily solid |
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liquid |
Mantle makes up 84% of the Earth's volume and has an average thickness of approximately 1,800 miles (2,900 km). It is dense, hot, and primarily solid although in places it behaves more like a viscous fluid as the plates of the upper mantle and crust gradually "float" along its circumference.