Which of the following is the correct conversion factor to convert kilograms (kg) to milligrams (mg)?

• A. 1 kg = 1,000 mg
• B. 1 kg = 1,000,000 mg
• C. 1 kg = 100,000 mg
• D. 1 kg = 10,000 mg

Answer: (B)

Verified step by step guidance

1. Recall the basic metric prefixes and their values relative to the base unit gram (g): kilo- (k) means 10^3 or 1,000 times the base unit, and milli- (m) means 10^-3 or one-thousandth of the base unit.
2. Understand that 1 kilogram (kg) is equal to 1,000 grams (g), because 'kilo' means 1,000 times the gram.
3. Recognize that 1 milligram (mg) is equal to 0.001 grams (g), since 'milli' means one-thousandth of a gram.
4. To convert kilograms to milligrams, first convert kilograms to grams, then convert grams to milligrams by multiplying by the appropriate factors: 1 kg = 1,000 g and 1 g = 1,000 mg.
5. Combine the two conversion steps into one conversion factor: multiply 1,000 (g/kg) by 1,000 (mg/g) to get 1,000,000 mg in 1 kg, so the correct conversion factor is \$1\ \text{kg} = 1,000,000\ \text{mg}$.