Each particle in an atom has mass. Electrons are approximately how many times lighter than protons?

• A. About 18 times lighter
• B. About 10,000 times lighter
• C. About 180 times lighter
• D. About 1,800 times lighter

Answer: (D)

Verified step by step guidance

1. Understand that the problem asks for the approximate ratio of the mass of a proton to the mass of an electron, i.e., how many times lighter an electron is compared to a proton.
2. Recall the approximate masses of the particles: the mass of a proton is about \$1.67 \times 10^{-27}\( kg, and the mass of an electron is about \)9.11 \times 10^{-31}$ kg.
3. Set up the ratio by dividing the mass of the proton by the mass of the electron: \(\frac{\text{mass of proton}}{\text{mass of electron}} = \frac{1.67 \times 10^{-27}}{9.11 \times 10^{-31}}\).
4. Perform the division by dividing the coefficients (1.67 by 9.11) and subtracting the exponents in the powers of ten (\(-27 - (-31) = 4\)), which gives the approximate factor by which the proton is heavier than the electron.
5. Interpret the result as the electron being approximately that many times lighter than the proton, which leads to the conclusion that electrons are about 1,800 times lighter than protons.