Fundamental particle masses: approximately how does the electron’s mass compare to the proton’s mass?

Difficulty: Easy

Correct Answer: 1/1836 of the proton mass

Explanation:


Introduction / Context:
Mass ratios among subatomic particles are constants used throughout atomic physics, spectroscopy, and accelerator calculations. The electron-to-proton mass ratio is a widely memorized benchmark value.


Given Data / Assumptions:

  • Proton rest mass ≈ 1.6726 × 10^-27 kg.
  • Electron rest mass ≈ 9.1094 × 10^-31 kg.
  • We consider rest masses, non-relativistic comparison.


Concept / Approach:

Divide electron mass by proton mass to obtain the ratio. The accepted approximate ratio is m_e/m_p ≈ 1/1836 (more precisely ≈ 1/1836.15). Hence, the electron is much lighter than the proton by roughly three orders of magnitude.


Step-by-Step Solution:

Recall numerical values for m_e and m_p.Compute ratio: m_e/m_p ≈ 9.11×10^-31 / 1.67×10^-27 ≈ 1/1836.State the approximate relationship used in problem solving.


Verification / Alternative check:

Tables of fundamental constants list m_p/m_e ≈ 1836.152673, confirming the common approximation 1/1836 for m_e/m_p.


Why Other Options Are Wrong:

equal, infinite, about half, 1836 times: All contradict well-established mass ratios from experiment.


Common Pitfalls:

Mixing up which particle is heavier; misplacing decimal exponents when estimating the ratio.


Final Answer:

1/1836 of the proton mass

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