Answer :
Final answer:
The mass of a grain of sand is approximately 2.8×10⁻⁸ milligrams
Explanation:
The mass of a grain of sand is approximately 2.8×10⁻¹¹ grams. To convert this into a more familiar unit, we can use the metric system prefixes. 1 gram is equal to 1000 milligrams, so 2.8×10⁻¹¹ grams would be equal to:
2.8×10⁻¹¹ grams × 1000 milligrams/1 gram = 2.8×10⁻⁸ milligrams
Therefore, the mass of a grain of sand is approximately 2.8×10⁻⁸ milligrams, which is represented by option A - Milligram.
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