When two electrical charges, of opposite sign and equal magnitude, are separated by a distance, a dipole is established. The size of a dipole is measured by its dipole moment . Dipole moment is measured in Debye units, which is equal to the distance between the charges multiplied by the charge
Dipolemoment 'D' = e x d where e= charge and d= distance by which charge is separated.
In this case e = charge on electron = 1.6 x10^-19 C
D = 1.6 x10^-19 C ( 1x10^-10 m) =1.6x10^-29 Cm