Electric field equals electric force over this quantity.
By Noether's theorem, gauge invariance of an electromagnetic field is the symmetry that leads to the conservation of this quantity. The sum of the time derivative of the density of this quantity and the divergence of the current density equals zero by the conservation of this quantity. Electric field equals electric force over this quantity. The energy stored in a capacitor is one half times voltage times this quantity, and capacitance is equal to this quantity over voltage. Name this quantity for which an electron has a negative value and a proton has a positive value.
By Noether's theorem, gauge invariance of an electromagnetic field is the symmetry that leads to the conservation of this quantity.
{charge}