EOLSS - Radiochemistry and Nuclear Chemistry

Table 1: Physical constants and units mentioned in the text. Following IUPAC recommendations, their symbols are in italics and in normal style, respectively. “Corresponds to” (denoted by the symbol  in the text) means a value given in a unit whose use is only justified through the proportionality between different physical quantities. Energy and mass are connected by the proportionality , energy and temperature by .

Physical constant or unit

Value

Name

Symbol

in SI unit

in other unit

corresponds to

elementary charge

 

1.60217653×1019 C

 

 

Avogadro number

 

6.0221415×1023 mol1

 

 

electron volt

eV

1.60217653×1019 J

 

96.485 kJ mol1
11.60451 kK

gigaelectron volt

GeV

1.60217653×1010 J

 

1.073544 u

Boltzmann constant

 

1.380650×1023 J K-1

8.61734×105 eV K-1

 

speed of light in empty space

 

2.99792458×108 m s-1

 

 

unified atomic mass unit (amu, a.m.u.)

u

1.6605387×1027 kg


1 Da

931.49401 MeV

electron mass

 

9.109382×1031 kg

5.48579911×104 u

510.9989 keV
0.5109989 MeV

proton mass

 

1.6726216×1027 kg

1.0072764669 u
1836.152668  

938.2720 MeV
0.938272 GeV

neutron mass

 

1.6749272×1027 kg

1.0086649158 u
1838.683655  

939.5654 MeV
0.9395654 GeV

neutrino mass

 

 

< 4×106  

< 2 eV

becquerel

Bq

1 s1

1 dps

 

curie

Ci

3.7×1010 Bq

 

 

Planck constant

 

6.6260688×1034 J s

4.1356673×1015 eV s

 

reduced Planck constant

 

1.0545716×1034 J s

6.5821189×1016 eV s

 

barn

b

1028 m2 = 100 fm2

 

 

year

a

3.1556952×107  s

365.2425 d