Which of the following is closest to the diameter of a proton (in nanometers)?

• A. 0.00084 nm
• B. 0.84 nm
• C. 8.4 nm
• D. 0.084 nm

Answer: (A)

Verified step by step guidance

1. Understand that the diameter of a proton is a very small length scale, typically measured in femtometers (fm), where 1 fm = 1 \times 10^{-15} meters.
2. Recall or look up the approximate diameter of a proton, which is about 1.7 femtometers (fm).
3. Convert the diameter from femtometers to nanometers (nm) using the conversion factors: 1 nm = 1 \times 10^{-9} meters and 1 fm = 1 \times 10^{-15} meters.
4. Set up the conversion calculation: \( \text{diameter in nm} = \text{diameter in fm} \times \frac{1 \times 10^{-15} \text{ m}}{1 \text{ fm}} \times \frac{1 \text{ nm}}{1 \times 10^{-9} \text{ m}} \).
5. Simplify the powers of ten to find the diameter in nanometers and compare the result to the given options to identify the closest value.