The "super-hot" earth's core is important because it generates the magnetic field around the earth. it also helps control evolution.
Answer:
Observations of the sky allowed explorers to mark the passage of time both in hours and through the months of the year. Early astronomers also realized that the night sky does not look the same from different places on the Earth.
First convert grams to moles:
90.0g *(mole/39.997) = 2.250mole
Remember that molarity is moles per liters:
2.250mol/3L = .750 M
Confidence is best
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