 To see that this is so, it suffices to consider the electron's charge and neglect its angular momentum.In the Reissner–Nordström metric, which describes electrically charged but non-rotating black holes, there is a quantity , defined by

where is the electron's charge and is the vacuum permittivity.For an electron with = − = , this gives a value

Since this (vastly) exceeds the Schwarzschild radius, the Reissner–Nordström metric has a naked singularity.