Final answer:
Half a milligram should be written as 0.5 mg or 500 mcg to avoid confusion, ensuring clarity, especially in critical fields like medicine. Conversion from milligrams to nanograms is done using metric system ratios, e.g., 0.5 mg equals 500,000 ng.
Step-by-step explanation:
To avoid confusion when writing half a milligram, it should be expressed using the appropriate metric prefix and unit. Half a milligram is best written as 0.5 mg or 500 micrograms (mcg). It's crucial to include both the number and the unit to properly express a quantity, avoiding any ambiguity or potentially dangerous situations, especially in fields like medicine.
When converting from milligrams to nanograms, you would use known ratios and the metric system's conversion factors. For example, to convert 0.5 mg to nanograms, since there are 1,000,000 nanograms (ng) in a milligram, the calculation would be 0.5 mg × 1,000,000 ng/mg = 500,000 ng.
Remember, clear and accurate unit conversion is a critical skill, especially in health-related professions where incorrect dosages can have severe consequences. As a rule, it's best to present units in a way that makes numbers manageable and clear, leading to fewer mistakes and clearer communication.