| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.27 |
| Score | 0% | 65% |
Which of the following substances gives up positively charged hydrogen ions (H+) when dissolved in water?
alkaline |
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acid |
|
solution |
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base |
An acid is a substance that gives up positively charged hydrogen ions (H+) when dissolved in water. A base (alkaline) gives up negatively charged hydroxide ions (OH-) when dissolved in water. pH is a scale that measures of how basic or acidic a solution is. Numbered from 0 to 14, solutions with a pH of 7 are neutral, less than 7 are acidic, more than 7 are alkaline.
The respiratory and circulatory systems are similar in that they:
add carbon dioxide |
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deoxygenate blood |
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transport nutrients |
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transport oxygen |
Like the respiratory system, the circulatory system serves to transport oxygen throughout the body while removing carbon dioxide. In addition, the circulatory system transports nutrients from the digestive system.
Generally, an atom has __________ negative electrons orbiting the nucleus as it does positive protons inside.
more |
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fewer |
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equal numbers of |
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double the number of |
An electron is a subatomic particle that orbits the nucleus of an atom. It carries a negative electric charge. Generally, an atom has the same number of negative electrons orbiting the nucleus as it does positive protons inside.
Which of the following does not represent the freezing point of water?
0°C |
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32°F |
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273K |
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0°F |
The Fahrenheit scale fixes the freezing point of water at 32°F, the Celsuis scale at 0°C, and the Kelvin scale at 273K.
Which of the following is not one of the outer planets?
Neptune |
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Venus |
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Uranus |
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Jupiter |
In contrast to the solid terrestrial planets, the outer planets (Jupiter, Saturn, Uranus, and Neptune) consist of hydrogen and helium gas and water.