Annex 2 – Units recognised in international practice as determined by the President under Rule 49(2) (see F‑II, 4.13)
3. Units used with the SI, and whose values in SI are obtained experimentally
The unified atomic mass unit is 1/12 of the mass of an atom of the nuclide 12C.
The electronvolt is the kinetic energy acquired by an electron passing through a potential difference of 1 volt in a vacuum.
Quantity |
Unit |
||
|---|---|---|---|
Name |
Symbol |
Value |
|
Mass |
unified atomic mass unit |
u |
1 u ≈ 1,6605655 x 10-27 kg |
Energy |
Electronvolt |
eV |
1eV ≈ 1,6021892 x 10-19 J |
The value of these units, expressed in SI units, is not known exactly.
The prefixes and their symbols listed in F‑II, Annex 2, 1.3 may be used in conjunction with these two units and with their symbols.