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Line 75: − == ==+ − − [[Avogadro's number]]: 6.02 x <math>10^{23}</math> particles/mole − − Planck's constant: 6.23 x <math>10^{-34} \frac{Joules}{Hertz}</math> − − R = 0.0821 <math>\frac{L \cdot atm}{mole \cdot K}</math> or 8.314 <math>\frac{J}{mole \cdot K}</math> − − == ==+
Started tidying it up, will tidy up formatting of values (i.e. units) later
This page lists various constants used in [[physics]] and some useful conversions.
==Physical constants==
The number in brackets represents the uncertainty in the constant, so that <math>6.626070040(81) \times 10^{-34}</math> has an uncertainty of <math>0.00000000081 \times 10^{-34}</math>.
{| class="wikitable"
|-
!Name
!Symbol
!Value
!Meaning
!Used in
!Exact
|-
|[[Planck's constant]]
|<math>h</math>
|<math>6.626070040(81) \times 10^{-34} \,</math> J s
|It relates the [[frequency]] of a [[photon]] to its [[energy]]
|[[Quantum mechanics]]
|Inexact<ref>http://physics.nist.gov/cgi-bin/cuu/Value?h</ref>
|-
|[[Speed of light]]
|<math>c</math>
|299,792,458 m s<sup>-1</sup>
|This is the speed of light in a [[vacuum]]
|Most of physics, such as [[optics]] and [[relativity]]
|Exact<ref>http://physics.nist.gov/cgi-bin/cuu/Value?c</ref>
|-
|Permittivity of free space
|<math>\epsilon_0</math>
|<math>8.854187817... \times 10^{-12}</math> F m<sup>-1</sup>
|Related to the strength of an [[electric field]] produced by a charge
|[[Electromagnetism]]
|Exact<ref>http://physics.nist.gov/cgi-bin/cuu/Value?ep0</ref>
|-
|Permeability of free space
|<math>\mu_0</math>
|<math>4 \pi \times 10^{-7}</math>
|Related to the strength of [[magnetic field]s produced by a [[current]]
|[[Electromagnetism]]
|Exact<ref>http://physics.nist.gov/cgi-bin/cuu/Value?mu0</ref>
|-
|Elementary charge
|<math>e</math>
|<math>1.6021766208(98) \times 10^{-19}</math> C
|The magnitude of the electric charge on an electron
|Determines the strength of electric and magnetic fields produced by [[proton]]s, [[electron]]s etc
|Inexact<ref>http://physics.nist.gov/cgi-bin/cuu/Value?e</ref>
|-
|[[Avogadro's number]]
|<math>N_A</math>
|<math>6.022140857(74) \times 10^{23}</math> mol<sup>-1</sup>
|The number of constituents in 1 mole of something
|[[Chemistry]], [[statistical mechanics]], [[thermodynamics]]
|Inexact<ref>http://physics.nist.gov/cgi-bin/cuu/Value?na</ref>
|-
|Ideal gas constant
|<math>R</math>
|<math>8.3144598(48)</math> J mol<sup>-1</sup> K<sup>-1</sup>
|Relates the [[pressure]], [[volume]], [[temperature]] and number of moles of an [[ideal gas]]
|[[Thermodynamics]]
|Inexact<ref>http://physics.nist.gov/cgi-bin/cuu/Value?r</ref>
|}
==Useful Conversions==
1 atm = 101.1 kPa
1 atm = 101.1 kPa
760 mm Hg = 1 atm
760 mm Hg = 1 atm
--------
Atomic mass unit: 1.00 amu = 1.67 x <math>10^{-27}</math>kg
Atomic mass unit: 1.00 amu = 1.67 x <math>10^{-27}</math>kg
Standard Temperature and Pressure (STP): temperature = 273 K and pressure = 1.00 atm
Standard Temperature and Pressure (STP): temperature = 273 K and pressure = 1.00 atm
---------
{| class="wikitable" style="text-align:left"
{| class="wikitable" style="text-align:left"