53 



TABLE 27.— TABLE OF LEAST-SQUARES ADJUSTED OUTPUT VALUES OF 

 PHYSICAL CONSTANTS (concluded) 



Mass-energy conversion factors 1 g = ( 5.60999 ± 0.00025) X 10 20 Mev 



1 electron mass = 0.510984 ± 0.000016 Mev 

 1 atomic mass unit = 931.162 ± 0.024 Mev 

 1 proton mass = 938.232 ± 0.024 Mev 

 1 neutron mass = 939.526 ± 0.024 Mev 

 Quantum energy conversion factors. .1 ev = ( 1.60207 ± 0.00007) X 10~ 12 erg 



E/P — (1.98620 ± 0.00016) X 10- 16 erg cm 

 E \ g - ( 12397.8 ± 0.5) X 10" s ev-cm 

 E X s = 12372.2 ± 0.4 k volt-x units 

 E/v = (6.6252 ± 0.0005) X 10^ erg sec 

 Eh— (4.13544 ±0.00015) X 10- 1! ev-sec 

 vIE = (5.0347 ± 0.0004) X 10 15 cm" 1 erg" 1 

 v/E = ( 8065.98 ± 0.30) cm' 1 ev" 1 

 v/E = (1.50938 ± 0.00012) X 10 20 sec" 1 erg" 1 

 v/E = (2.41812 ± 0.00009) X 10 u sec" 1 ev" 1 

 de Broglie wavelengths, \n of elementary 

 particles c 



Electrons X D . = ( 7.27373 ± 0.00016) cm 2 sec"7v 



= (1.55226 ± 0.00008) X 10- 13 cm (erg)»/V_E_ 

 = (1.226377 ± 0.000032) X 10- 7 cm (ev)tyV E 



Protons \ np = (3.96145 ± 0.00013) X 10" 3 cm 2 sec- l /v 



= (3.62261 ± 0.00020) X 10" 15 cm (erg)*/V_£ 

 = (2.86208 ± 0.00012) X 10" 9 cm (ev)VV E 



Neutrons X D „ = (3.95599 ± 0.00013) X 10" 3 cm 2 sec"*/v 



= (3.62005 ± 0.00020) X 10- 15 cm (erg)VV E 

 = (2.86005 ± 0.00012) X 10~ 9 cm (ev)VV E 



Energy of 2200 m/sec neutron £„„ = 0.0252977 ± 0.0000006 ev 



Velocity of 1/40 ev neutron. tw = 2187.017 ± 0.028 m/sec 



The Rvdberg and related derived constants 



R* = 109737.309 ± 0.012 cm" 1 

 /?xc= (3.289847 ± 0.000008) X lO^sec' 1 

 R*hc= (2.17961 ±0.00018) X 10' 11 ergs 



RJic* V 10" 8 



A iv _ _ j 3 605Q ± 00Q5 ev 



e 

 Hydrogen ionization potential /o = 13,5978 ± 0.0005 ev 



= ^[ 1 + ^ + ..] 



xio- 



c These formulas apply only to non-relativistic velocities. If the velocity of the particle is not negligi- 

 ble compared to the velocity of light, c, or the energy not negligible compared to the rest mass energy, 

 we must use \d = Xc[e(e + 2)]- 1 ' 2 where \c is the appropriate Compton wavelength and e is the kinetic 

 energy measured in units of the particle rest mass. 



SMITHSONIAN PHVSICAL TABLES 



