Physical and Chemical Constants
- Practical Electron Microscopy and Database -
- An Online Book -

http://www.globalsino.com/EM/  



 

 

=================================================================================

Physical and chemical constants 
Comments
a0 0.053 nm Bohr radius
c ligh speed in vacuum = 2.99792 × 108 m/s The speed of light in vacuum
P 1.01325 × 105 N/m2 Standard atmosphere
1 barn 10-24 cm2
1 Degree (°) 0.017453293 radian [rad]
1 k 1.38064852 × 10-23 J/K (or m2 kg s-2 K-1) (R/NAVO) Boltzmann constant
1 eV 1.60218 x 10-19 J = 23.053 kcal/mol
1 q 1.6021766208 x 10-19 C Elementary charge
1 kcal/mol 4.184 kJ/mol Or convert with excel file
1 kJ/mol 0.010364512 eV/bond Or convert with excel file
1 NAVO 6.02214086 × 1023 mol-1 Avogadro's constant
1 MeV/cm 1.602 x 10-11 J/m
1 Pa (pascal) 0.00001 bar = 1 x 10-5 bar Pa is in the SI system.
1 Pa (pascal ) 0.0075006375541921 Torr ≈ 7.5 x 10-3 Torr
1 Pa 1 newton/m2
1 mmHg (10-3mHg) 1 torr
1 m0 9.1095 × 10−31 kg, or 5.489×10−4 atomic mass units Electron rest mass
1 Mp 1.67264 × 10-27 kg Proton rest mass
R 1.98719 cal mol-1K-1 Gas constant
1 radian [rad] 57.3 Degree (°)
1 angstrom (Å)  1 Å = 1 x 10-10 m = 1 x 10-4 µm
1 nm   1 x 10-9 m
1 oz 0.00625 lb 
1 g 0.035274 oz
1 kT/q 0.0259 V Thermal voltage at 300 K
ε0 8.854 × 10−12 farad/m = 8.85418 × 10−14 F/cm (1/µ0c2) Permittivity of of vacuum
µ0 4π × 10−7 henry/m = 1.25663 × 10−8 H/cm (4π×10−9) Permeability of vacuum
h 6.62617 x 10-23 ergs/sec = 6.62617 x 10-34 m2 kg/s = 6.62617 x 10-34 J-s Planck's constant
hc 1239.84 eV nm h: Planck's constant; c: Speed of light.
λ 1.23977 µm Wavelength of 1-eV quantum
λ (nm)
wavelength of radiation Wavelength of photons

 

 

=================================================================================