NEET 2017 Physics and Chemistry

Suppose the charge of a proton and an electron differ slightly. One of them is – e, the other is (e +Δe). If the net of electrostatic force and gravitational force between two hydrogen atoms placed at a distance d (much greater than atomic size) apart is zero, then Δe is of the order of [Given mass of hydrogen mh=1.67×10−27kg]