ANS:B - 1837

To find the ratio of the mass of a proton to that of an electron, we can use the known ratio of the mass of a neutron to that of an electron and the fact that a neutron and a proton have approximately the same mass. Given:

• Mass of a neutron to that of an electron = 1839

Since a proton and a neutron have approximately the same mass, we can use this ratio to find the ratio of the mass of a proton to that of an electron: Ratio of mass of proton to electron=Mass of neutron/Mass of electron Ratio of mass of proton to electron=1839/1​ Therefore, the ratio of the mass of a proton to that of an electron is 1839.