Plutonium-32 has a half-life of 14.2 days. After 99.4 days, how much of what was originally a 499.2 gram sample remains? 14 grams

3.9 grams

35.7 grams

0.71 grams

Explanation:

A half-life is simply the amount of time it takes for a substance to reduce itself by half. In this case, every 14.2 days half of plutonium-32 is converted into something else. All you have to do is divide 99.4 by 14.2, which is exactly 7. About 0.78% of the plutonium will be remaining at this time.

that tool is called an altimeter which measures your altitude which can be used to tell which atmosphere you are currently in, including the stratosphere.

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