Impeller, centrifugal pump and electric pump

An impeller is provided, which includes an upper plate, blades, and a lower plate. The blades are arranged between the upper plate and lower plate. The upper plate includes an upper surface and a lower surface, the blades are integrally formed with the upper plate by injection molding, and the blades are located at the lower surface of the upper plate. The blades include first blades. Each of the first blades includes one arc, a combination of multiple arcs, or a combination of multiple arcs and straight lines. The first blades are uniformly distributed along a circumference of the upper plate, and the first blade includes a first tail, and the first tail of the first blade make a first side of the first blade have no intersection with an outer edge of the upper plate.