Two protons in a molecule are $4\mathrm{.}1010-10$ m apart. Find the electric force exerted by one proton on the other.

magnitude Ndirection $---$Select$---$ attractive repulsive

$($b$)$ State how the magnitude of this force compares with the magnitude of the gravitational force exerted by one proton on the other.

FeFg

$=$

$($c$)$ What must be a particle's charge$-$to$-$mass ratio if the magnitude of the gravitational force between two of these particles is equal to the magnitude of electric force between them?

C$/$kg