Question

from cathode ray experiments, j. j. thomson estimated that the mass of an electron was "about a thousandth" of the mass of a proton. how accurate is that estimate? calculate the ratio of the mass of an electron to the mass of a proton.

Answer 1

mass of a proton is: 2.67 • 10^-27 kg
mass of an electron is: 9.11 • 10^-31 kg

mass of an electron/ mass of a proton:

(9.11 • 10^-31 / 2.67 • 10^-27)
= 0.0003411...

This ratio is closest to a ten-thousandth. Therefore, the statement is not accurate.