no it is kilogram
A hydrogen atom of the most common isotope of hydrogen, or a proton or neutron.
a proton
John Dalton suggested it, but Francis Aston was the one who defined it's size
The mass of an electron is: 0.000548579867 atomic mass units (amu)or,9.10938188 × 10-31 kilograms or,9.10938188 × 10-28 grams