Convert from electronvolt to livre [France]

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 (livre [France])
The livre is a traditional unit of weight in French speaking countries and in Greece. The livre corresponds to the English pound and to the Spanish libra. The livre is divided into 2 marcs or into 16 onces. The French livre varied from market to market, but the official standard from about 1350 to the introduction of the metric system was the livre poids de marc or livre de Paris of 489.5 grams (1.079 English pounds). In modern France, the livre is used as an informal metric unit equal to exactly 500 grams or 0.5 kilogram (1.1023 pounds). The traditional Greek livre is also about 500 grams.