| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.31 |
| Score | 0% | 66% |
212°F is how many °C?
0 |
|
-100 |
|
\(135 {5 \over 9}\) |
|
100 |
The formula to convert from F° to C° is:
\(C° = {5 \over 9} (F° - 32)\)
plugging in our values gives:
\(C° = {5 \over 9} (212 - 32)\)
\(C° = {5 \over 9} (180) = {{180 \times 5} \over 9}\)
\(C° = {900 \over 9}\)
\(C° = 100\)
Generally, an atom has __________ negative electrons orbiting the nucleus as it does positive protons inside.
double the number of |
|
more |
|
fewer |
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equal numbers 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.
Examples of secondary consumers include:
chickens |
|
grasshoppers |
|
plankton |
|
wolves |
Secondary consumers (carnivores) subsist mainly on primary consumers. Omnivores are secondary consumers that also eat producers. Examples are rats, fish, and chickens.
Arteries carry __________ blood at __________ pressure.
deoxygenated, low |
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deoxygenated, high |
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oxygenated, high |
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oxygenated, low |
Veins carry blood back to the heart from the body. While arteries are thick-walled because they carry oxygenated blood at high pressure, veins are comparatively thin-walled as they carry low-pressure deoxygenated blood. Like the heart, veins contain valves to prevent blood backflow.
pH is a scale that measures of how basic or acidic a solution is. A solution with a pH of 4 is:
alkaline |
|
acidic |
|
basic |
|
neutral |
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.