about eV conversions?

Question

why 1eV = 1.6 x 10^-19 J? thx

Answer 1

voltage is defined as
1J/1 C (1)
1 joule of work must be done to take 1 charge through a potential difference of 1 V
so in an E field what do we get
N/C = V/m (2)
and finally since a charge is 1.6x10^-19 C
1 eV = 1.6x10^-19 C V = 1.6x10^-19 J

Answer 2

because it is the amount of work required to take a unit charge through a pot. of 1V