In a young’s double-slit experiment that uses electrons, the angle that locates the first-order bright fringes is θa = 4.0 × 10-4 degrees when the magnitude of the electron momentum is pa = 1.2 × 10-22 kg*m/s. with the same double slit, what momentum magnitude pb is necessary so that an angle of θb = 8.0 × 10-4 degrees locates the first-order bright fringes?