| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.67 |
| Score | 0% | 53% |
Which of these is matter than cannot be separated into different types of matter by ordinary chemical methods?
element |
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compound |
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atom |
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molecule |
An element is matter than cannot be separated into different types of matter by ordinary chemical methods.
In fermentation, what replaces oxygen in anaerobic respiration?
starches |
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water |
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lactic acid or alcohol |
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ascorbic acid or peptides |
If no oxygen is present, cellular respiration is anaerobic and will result in fermentation where either lactic acid or alcohol is used instead of oxygen.
-40°F is how many °C?
-40 |
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\(-{40 \over 9}\) |
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-8 |
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\({40 \over 9}\) |
The formula to convert from F° to C° is:
\(C° = {5 \over 9} (F° - 32)\)
plugging in our values gives:
\(C° = {5 \over 9} (-40 - 32)\)
\(C° = {5 \over 9} (-72) = {{-72 \times 5} \over 9}\)
\(C° = {-360 \over 9}\)
\(C° = -40\)
Scalar quantities are fully described by which of the following?
a magnitude only |
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a magnitude and a polarity |
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a magnitude and a direction |
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a direction only |
Velocity and displacement are vector quantities which means each is fully described by both a magnitude and a direction. In contrast, scalar quantities are quantities that are fully described by a magnitude only. A variable indicating a vector quantity will often be shown with an arrow symbol: \(\vec{v}\)
pH is a scale that measures of how basic or acidic a solution is. A solution with a pH of 9 is:
acidic |
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neutral |
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water |
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alkaline |
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.