Fundamental Physical Constants

Fundamental Physical Constants
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Fundamental Physical Constants

 

Certain physical constants have special importance on account of their universality or place in fundamental theory. These constants are given below in SI units. The figure in brackets is the estimated uncertainty in the last digit.

 

Table 1: Physical Constants - General Constants
Quantity Symbol Value Unit
Speed of light in vacuum
c
2.997924590(8) * 108
m.s-1
Planck constant
h
6.62620(5) * 10-34
J.Hz-1
Electron charge
e
1.602192(7) * 10-19
C
Gas constant
R
8.31
J.K-1.mol-1
Gravitational constant
GN
6.673 * 10-11
m3 kg-1 s-2
Standard grav. accel., sea level
gn
9.806 * 105
kg

 

 

Table 2: Physical Constants - Electron Constants
Quantity Symbol Value Unit
Electron rest mass
me
9.10956(5) x 10-31
kg
Electron rest energy
mec2
8.18726(6) x 10-14
J
Electron charge-mass ratio
e/me
1.758803(5) x 1011
C.kg-1
Radius of electron
re
2.817939(13) x 10-15
m

 

 

Table 3: Physical Constants - Proton Constants
Quantity Symbol Value Unit
Proton rest mass
mp
1.672614(11) x 10-27
kg
Proton rest energy
mpc2
1.503271(15) x 10-10
J
Proton charge-mass ratio
e/mp
9.57897(11) x 107
C.kg-1

 

 

Table 4: Physical Constants - Neutron Constants
Quantity Symbol Value Unit
Neutron rest mass
mn
1.674920(11) x 10-27
kg
Neutron rest energy
mnc2
1.505343(15) x 10-10
J

 

 

Table 5: Physical Constants - Atomic Constants
Quantity Symbol Value Unit
Rydberg constant
R
1.0973731(1) * 107
m-1
Bohr radius
ao
5.291772(8) * 10-11
m
Bohr magneton
µ
9.27410(6) * 10-24
J.T-1
Nuclear magneton
µn
5.05095(5) * 10-27
J.T-1
Zeeman splitting constant
µ/hc
4.66860(7) * 101
m-1T-1

 

 

Table 6: Physical Constants - Matter Constants
Quantity Symbol Value Unit
Avogadro constant
N
6.02217(4) * 1023
mol-1
Faraday
F
9.64867(5) * 104
Cmol-1
Normal volume of ideal gas
Vo
2.24136(30) * 10-2
m3.mol-1
Gas constant
R
8.3143(3) * 100
J.K-1mol-1
Boltzmann constant
k
1.38062(6) * 10-23
J.K-1

 

 

Table 7: Units of Gas Constant (R)
Quantity Symbol Value Unit
Gas contant
R
8.3143(3)
J.K-1mol-1

R = 8.3143(3) J.K-1.mol-1 = 1.98 cal/deg.mol = 82.05 cm3 atm deg-1 mol-1

 

 

Table 8: Units of Pressure
Quantity Symbol Value Unit
Pressure
P
1 N.m-2 = 1 Pa
Pa = N.m-2

Pressure is measured in N.m-2 = 1 Pa

1 atm = 760 mmHg = 101325 kPa

 

 

Table 9: SI Prefixes
Name Symbol Value  
pico
p
10-12
  
nano
n
10-9
  
micro
µ
10-6
  
milli
m
10-3
  
centi
c
10-2
  
deci
d
10-1
  
kilo
k
103
  
mega
M
106
  
giga
G
109
  
tera
T
1012
  

 

 

References

  1. P.J. Mohr and B.N. Taylor, J. Phys. Chem. Ref. Data, 28, 1713 (1999)
  2.  P.J. Mohr and B.N. Taylor, Rev. Mod. Phys., 72, 351 (2000)
  3. Physical Constants
  4. R.M. Tennent, "Science Data Book", Oliver & Boyd, (1979)

Key Terms

fundamental physical constants, chemical data, physical data, thermochemical data

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