The charge on one electron is 1.602 x 10⁻¹⁹ of a Coulomb.
THAT much charge every second is THAT many Amperes of current.
1000 elctrons/minute = (1000/60) electrons per second.
They carry (1000/60) x (1.602 x 10⁻¹⁹) Coulombs of charge per second.
That's (1000/60) x (1.602 x 10⁻¹⁹) Amperes of current.
(1000/60) x (1.602 x 10⁻¹⁹) Ampere =
(1602/60) x 10⁻¹⁹ Ampere =
2.67 x 10⁻¹⁸ Ampere .