formula to find the mass of an electron
Mass-to-charge ratio Some fields use the charge-to-mass ratio (Q/m) instead, which is the multiplicative inverse of the mass-to-charge ratio. The 2014 CODATA recommended value for an electron is  e⁄me = - 7011175882002400000♠1.758820024(11)×1011 C/kg.[2]
Isoelectric point For an amino acid with only one amine and one carboxyl group, the pI can be calculated from the mean of the pKas of this molecule.[4]
Atom Every atom is composed of a nucleus and one or more electrons bound to the nucleus. The nucleus is made of one or more protons and typically a similar number of neutrons. Protons and neutrons are called nucleons. More than 99.94% of an atom's mass is in the nucleus. The protons have a positive electric charge, the electrons have a negative electric charge, and the neutrons have no electric charge. If the number of protons and electrons are equal, that atom is electrically neutral. If an atom has more or fewer electrons than protons, then it has an overall negative or positive charge, respectively, and it is called an ion.
Coulomb Since the charge of one electron is known to be about 6981160217662079999♠1.6021766208(98)×10−19 C,[7] 1 C can also be considered the charge of roughly 6.241509×10^18 electrons or +1 C the charge of that many positrons or protons, where the number is the reciprocal of 1.602177×10^−19.