Approximately how many times heavier is a proton than an electron?

• A. 1000 times
• B. 1838 times
• C. 10 times
• D. 2 times

Answer: (B)

This question tests how much heavier a proton is compared with an electron. The proton mass is about 1.6726 × 10^-27 kg and the electron mass is about 9.109 × 10^-31 kg. Dividing gives roughly 1.6726e-27 / 9.109e-31 ≈ 1.836 × 10^3, so the proton is about 1836 times heavier than the electron. The option 1838 times is a close, reasonable rounded value to use. The other numbers are off by large factors: 1000 times is too small, and 10 or 2 are far too small.