Q.Arrange electron (e), proton (p) and deutron

Specific charge $q/m$ is largest for the lightest particle (electron) and smallest for the heaviest (deuteron), giving the increasing order deuteron, proton, electron.

Specific charge (charge-to-mass ratio) is defined as $\dfrac{q}{m}$, and it is exactly this ratio that a Bainbridge-type mass spectrometer or a Thomson $e/m$ apparatus measures via the radius of circular deflection in a magnetic field ($r = \dfrac{mv}{qB}$, so $\dfrac{q}{m}=\dfrac{v}{rB}$).

For the electron, the charge magnitude is the elementary charge $e = 1.6\times10^{-19}$ C, and its mass is extremely small, $m_e = 9.11\times10^{-31}$ kg, giving a specific charge $\dfrac{e}{m_e}\approx 1.76\times10^{11}$ C/kg — by far the largest of the three, because the electron is thousands of times lighter than the proton for the same magnitude of charge.

For the proton, the charge is also $+e$, but the mass is $m_p = 1.67\times10^{-27}$ kg (about 1836 times the electron's mass), giving $\dfrac{e}{m_p}\approx 9.58\times10^{7}$ C/kg.

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