The ScientificConstants package provides access to the values of various constant physical quantities, for example, the velocity of light and the atomic weight of sodium. These values are required to solve equations in fields such as chemistry and physics. The ScientificConstants package also provides the units for each of the constant values, allowing for greater understanding of the equation as well as units matching for error checking of the solution.

The quantities available in the ScientificConstants package are divided into two distinct categories.

physical constants

properties of the chemical elements (and their isotopes)

$\mathrm{with}\left(\mathrm{ScientificConstants}\right)\:$

$\mathrm{GetConstant}\left(c\right)$

$\mathrm{speed\_of\_light\_in\_vacuum},\mathrm{symbol}=c,\mathrm{value}=299792458,\mathrm{uncertainty}=0,\mathrm{units}=\frac{m}{s}$

$\mathrm{evalf}\left(\mathrm{Constant}\left(c\right)\right)$

$2.99792458{10}^8$

$\mathrm{evalf}\left(\mathrm{Constant}\left(c\,\mathrm{units}\right)\right)$

$2.99792458{10}^8⟦\frac{m}{s}⟧$

$\mathrm{GetElement}\left(\mathrm{Na}\right)$

$11,\mathrm{symbol}=\mathrm{Na},\mathrm{name}=\mathrm{sodium},\mathrm{names}=\left\{\mathrm{sodium}\right\},\mathrm{atomicweight}=\left[\mathrm{value}=22.989770\,\mathrm{uncertainty}=2.{10}^{\mathrm{-6}}\,\mathrm{units}=\mathrm{amu}\right],\mathrm{ionizationenergy}=\left[\mathrm{value}=5.1391\,\mathrm{uncertainty}=\mathrm{undefined}\,\mathrm{units}=\mathrm{eV}\right],\mathrm{electronaffinity}=\left[\mathrm{value}=0.547926\,\mathrm{uncertainty}=0.000025\,\mathrm{units}=\mathrm{eV}\right],\mathrm{electronegativity}=\left[\mathrm{value}=0.93\,\mathrm{uncertainty}=\mathrm{undefined}\,\mathrm{units}=1\right],\mathrm{density}=\left[\mathrm{value}=0.97\,\mathrm{uncertainty}=\mathrm{undefined}\,\mathrm{units}=\frac{g}{{\mathrm{cm}}^3}\right],\mathrm{boilingpoint}=\left[\mathrm{value}=1156.\,\mathrm{uncertainty}=\mathrm{undefined}\,\mathrm{units}=K\right],\mathrm{meltingpoint}=\left[\mathrm{value}=370.87\,\mathrm{uncertainty}=\mathrm{undefined}\,\mathrm{units}=K\right]$

$\mathrm{evalf}\left(\mathrm{Element}\left(\mathrm{Na}\,\mathrm{atomicweight}\right)\right)$

$3.817543727{10}^{\mathrm{-26}}$

$\mathrm{GetIsotopes}\left(\mathrm{element}=\mathrm{Na}\right)$

${\mathrm{Na}}_{18},{\mathrm{Na}}_{19},{\mathrm{Na}}_{20},{\mathrm{Na}}_{21},{\mathrm{Na}}_{22},{\mathrm{Na}}_{23},{\mathrm{Na}}_{24},{\mathrm{Na}}_{25},{\mathrm{Na}}_{26},{\mathrm{Na}}_{27},{\mathrm{Na}}_{28},{\mathrm{Na}}_{29},{\mathrm{Na}}_{30},{\mathrm{Na}}_{31},{\mathrm{Na}}_{32},{\mathrm{Na}}_{33},{\mathrm{Na}}_{34},{\mathrm{Na}}_{35}$