Say it
(e - ) Compare with proton and neutron .
A fundamental consituent of matter, having a negative charge of 1.602 176 462 × 10 -19 coulombs ± 0.000 000 063 × 10 -19 coulombs and a mass of 9.109 381 88 × 10 -31 kg ± 0.000 000 72 × 10 -31 kg [ 1998 CODATA values ].