def speed_average(Temperature,element,isotope):
    r"""This function calculates the average speed (in meters per second)
    of an atom in a vapour assuming a Maxwell-Boltzmann velocity distribution.
    This is simply

    sqrt(8*k_B*T/m/pi)

    where k_B is Boltzmann's constant, T is the temperature (in Kelvins) and
    m is the mass of the atom (in kilograms).

    >>> print speed_average(25+273.15,"Rb",85)
    272.65940782

    >>> print speed_average(25+273.15,"Cs",133)
    217.938062809

    """
    atom = Atom(element, isotope)
    return sqrt(8*k_B*Temperature/atom.mass/pi)
def speed_average ( Temperature , element , isotope ) : atom = Atom ( element , isotope ) return sqrt ( 8 * k_B * Temperature / atom . mass / pi )
r"""This function calculates the average speed (in meters per second)
    of an atom in a vapour assuming a Maxwell-Boltzmann velocity distribution.
    This is simply

    sqrt(8*k_B*T/m/pi)

    where k_B is Boltzmann's constant, T is the temperature (in Kelvins) and
    m is the mass of the atom (in kilograms).

    >>> print speed_average(25+273.15,"Rb",85)
    272.65940782

    >>> print speed_average(25+273.15,"Cs",133)
    217.938062809