Environmental Engineering Reference
In-Depth Information
Appendix A
Physical Constants and Units
Ta b l e A . 1
Physical constants.
10
28
g
m
e
D
Electron mass
9.10939
10
24
g
Proton mass
m
p
D
1.67262
12
m
(
12
C)
1
10
24
g
Atomic mass unit
m
a
D
D
1.66054
Ratio of proton and electron masses
m
p
/
m
e
D
1836.15
Ratio of atomic and electron masses
m
a
/
m
e
D
1822.89
10
19
C
10
10
esu
Electron charge
e
D
1.602177
D
4.8032
e
2
10
19
erg cm
D
2.3071
10
27
erg s
Planck constant
h
D
6.62619
10
27
erg s
„D
1.05457
10
10
cm/s
Light velocity
c
D
2.99792
e
2
/(
Fine-structure constant
α
D
„
c
)
D
0.07295
c
/
e
2
Inverse fine-structure constant
1/
α
D„
D
137.03599
2
/(
m
e
e
2
)
Bohr radius
a
0
D„
D
0.529177 Å
m
e
e
4
/(2
2
)
10
18
J
Rydberg constant
R
D
„
D
13.6057 eV
D
2.17987
Bohr magneton
μ
B
D
e
„
/(2
m
e
c
)
10
24
J/T
D
9.27402
10
21
erg/G
D
9.27402
10
23
mol
1
Avogadro number
N
A
D
6.02214
2
/(60
3
c
2
)
10
12
W/(cm
2
K
4
)
Stefan-Boltzmann constant
σ
D
π
„
D
5.669
Molar volume
R
D
22.414 l/mol
10
19
cm
3
Loschmidt number
L
D
N
A
/
R
D
2.6867
Faraday constant
F
D
N
A
e
D
96485.3 C/mol
