| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.18 |
| Score | 0% | 64% |
The number system most used in science is the:
English system |
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British system |
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American system |
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metric system |
The metric system is a number system that designates one base unit for each type of measurement. For example, the base unit for length is the meter and the base unit for mass is the gram.
Which of the following states of matter exists at the highest temperature?
liquid |
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none of these |
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solid |
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gas |
Solids exist at a lower temperature than liquids which exist at a lower temperature than gases.
Which of the following is the formula for power?
\(P = \vec{w}t\) |
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\(P = {w \over t}\) |
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\(P = w t\) |
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\(P = {\vec{w} \over t}\) |
Power is the rate at which work is performed or work per unit time: \(P = {w \over t}\) and is measured in watts (W).
Which of the following is not a characteristic of the Sun?
is composed of hydrogen and helium |
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is a yellow dwarf star |
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makes up over 99% of the mass of the solar system |
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formed 2.6 billion years ago |
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.
A compound is a substance containing two or more different chemical elements bound together by what kind of bond?
molecular |
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covalent |
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ionic |
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chemical |
A compound is a substance containing two or more different chemical elements bound together by a chemical bond. In covalent compounds, electrons are shared between atoms. In ionic compounds, one atom borrows an electron from another atom resulting in two ions (electrically charged atoms) of opposite polarities that then become bonded electrostatically.