Metric Prefix Conversion: Millimeters to Nanometers

Steps:

• Recall that 1 millimeter (mm) = 10^{-3} meters.
• Recall that 1 nanometer (nm) = 10^{-9} meters.
• To find nm in 1 mm, divide the mm value in meters by the nm value in meters: 10^{-3} / 10^{-9} = 10^{6}.
• Thus, 1 mm = 1,000,000 nm.

Why D is correct:

• D (1,000,000) matches the calculation from metric definitions, where the exponent difference between mm (10^{-3}) and nm (10^{-9}) is 10^{6}.

Why the others are wrong:

• A (1,000): Equals micrometers in 1 mm (10^{3}), not nanometers.
• B (10,000): Incorrect; no standard prefix yields 10^{4} for this conversion.
• C (100,000): Incorrect; no standard prefix yields 10^{5} for this conversion.

Final answer: D