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Guidelines for Examination

 
 
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.