Convert from electronvolt to quintal [Portugal]

Unit Definition (electronvolt)
The electronvolt is a unit of mass used in particle physics. Mass and energy are related by Einstein's famous equation, E = mc². The constant c is the speed of light, 299.79 x 10E6 m/sec. An energy of 1 electronvolt is therefore equivalent to a mass of about 1.782 662 x 10E-33 gram, or about 1.073 544 x 10E-9 atomic mass unit.

Unit Definition (quintal [Portugal])
The quintal [Portugal] is a traditional unit of weight in Portugal. The Portuguese quintal is equal to 128 libras (about 129.5 pounds or 58.75 kilograms).