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Constants
A to B
C to D
E to F
G to I
J to L
M
N to Q
R to T
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Science

Constants - A to B


Aa
 |  Bb
A to B | C to D | E to F | G to I | J to L | M | N to Q | R to T | U to Z

  Aa  
    Name Symbol Value  
           
  Absolute Entropy constant Absolute Entropy Constant S0/R −1.164 8678 ± 0000044 at 1 K and 1 01 325 Pa  
           
    Absolute Zero      
           
  Acceleration of free fall on Earth Acceleration of Free Fall on Earth g 9.780 356 m s−2 at sea level on the equator
9.812 420 m s−2 at sea level in London
9.832 079 m s−2 at sea level at the poles
 
           
    Acceleration of free fall on the Sun   273.98 m s-2
27.938 g
 
           
    Acceleration of free fall on the Moon   1.62 m s-2
0.165 g
 
           
  Acre Acre   4046.856 42240 m2
 
           
    Aeon
Eon
Astrophysical 109 years  
           
  Alpha particle mass Alpha particle mass mα 6.644 655 98 ± 0.00000052 × 10-27 kg
4.001 506 1747 ± 0.0000000010 u
5.97191897 ± 0.00000047 × 10-10J/c2
3727.379 04 ± 0.00015 MeV/ c2
 
           
  Alpha particle to proton mass ratio Alpha particle to proton mass ratio mα/mp 3.972 599 6846 ± 0.0000000011  
           
  Alpha particle to electron mass ratio Alpha particle to electron mass ratio mα/me 7294.299 508 ± 0.000016  
           
    Air, Critical Temperature of   -190 °C
 
        183 K  
           
    Air, Density of   0.7734 m 3  kg−1
 
        1.2929 kg m −3  
           
    Air, Viscosity of (20°C) η0 1.8 × 10 -5 N s m−2  
           
  Alladi-Grinstead Constant Alladi-Grinstead Constant   0.809 394 020 534   
           
  Angstrom Ångström Å 10 −10 m  
           
    Anker   8.5 UK gallons
38.641 765 × 10-3 m3
 
           
  Annee-Lumiere Année-lumière ly 9.46052973 × 1010 m  
           
  Apery's COnstant Apéry's Constant ζ(3) 1.202 056 903  
           
  Apothecaries Ounce Apothecaries' Ounce oz (apoth)
3.110 347 680 × 10−2 kg  
      oz (ap.)    
           
  Archemedes' Constant Archimedes' Constant π 3.14 159 265 358 979 323 846 264 338 32795  
           
    Are a 100 m2  
           
  AU Astronomical Unit AU 1.495 978 706 60 ± 0.000 000 000 20 × 1011 m  
           
    Atmospheric Pressure
Standard atmospheric pressure
  1.01325 × 10 5  N m−2  
        1.01325 bar
 
        14.7 lbf in−2  
           
  Atomic Mass Unit Atomic Mass Unit
Dalton
amu 1.660 53873 ± 0.00000013 × 10−27 kg  
      mu 931.494 013 ± 0.000037 MeV
 
      u 1.492 41778 ± 0.00000012 × 10−10 J  
           
  Avogadro Constant Avogadro Constant NA 6.022 14199 ± 0.00000047 × 1023  mol−1  
           
  Avoirdupois Ounce Avoirdupois Ounce oz (avdp) 2.834 952 313 × 10−2 kg
 
      oz (av.) 0.0625 lb (av.)
 
      oz 16 drachms (av.)  
     
 
 
 
Aa
 |  Bb
To the top | To the bottom
A to B | C to D | E to F | G to I | J to L | M | N to Q | R to T | U to Z

 
   
   
   
   
  Bb  
    Name Symbol Value  
           
  maths constant Backhouse's Constant   1.456 074 948 582 689 671 399 595 351 116 54356  
           
  Base of Natural Logarithms Base of Natural Logarithms e 2.718 281 828 459 045 235 360 287 471 3526   
           
    Bar bar 105 Pa  
           
    Barn b 10-28 m2  
           
    Becquerel Bq    
           
  Bernstein's Constant Bernstein's Constant β 0.280 169 4990  
           
  Board Foot Board Foot   144 in3
2.359 737 216 × 10 −3  m3
 
           
  Bohr Magneton Bohr Magneton µB 9.274 00899 ± 0.00000037 × 10 −24 J T−1
 
        5.788 381 749 ± 0.00000043 × 10−5 eV T−1
 
        1.399 624 624 ± 0.000000056 × 1010 Hz T−1  
           
  Bohr Radius Bohr Radius a0 5.291 772 083 ± 0.000000019 × 10 −11 m  
           
  Boltzmann Constant Boltzmann Constant kB 1.380 6503 ± 0.0000024 × 10 −23 J K−11
 
        8.617 342 ± 0.000015 × 10 −5 eV K −11  
        2.083 6644 ± 0.0000036 × 1010 Hz K −11  
           
  Briggsian (common) logarithm of 2 Briggsian (common) logarithm of 2 log 10 2 0.301 029 995 663 981 19521  
           
    British thermal unit Btu 1.055 06 × 103 J  
           
  Brun's Constant Brun's Constant B 1.9021605824  
           
    Bushel   64 pint
3.636 8704 × 10-2 m3
 
           
    Bushel (US)   64 dry pints (US)
3.523 904 × 10-2 m3
 
           
    Butt   108 gallons of beer (UK gallons in the UK, US gallons in the US)
126 gallons of wine (UK gallons in the UK, US gallons in the US)
 
           
 
 
 

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