Interstellar space has an average temperature of about 10 K and an average density of hydrogen atoms of about one hydrogen atom per cubic meter. Calculate the mean free path of hydrogen atoms in interstellar space. Take d = 100 pm for a hydrogen atom.

Respuesta :

Answer:

The mean free path is [tex]0.0000373631 m[/tex]

Explanation:

The formula for mean free path is :

λ = [tex]\frac{V}{\sqrt{2}\pi d^{2}N  }[/tex]

where,

λ - is the mean free path distance

V - volume of the gas

d - the diameter of the molecule

N - number of molecules.

now ,

density [tex]D[/tex] = [tex]\frac{mass}{volume}[/tex] = [tex]\frac{M}{V}[/tex] ;

mass of the gas = (number of molecules)[tex]*[/tex](mass of one molecule) ;

as it's atomic hydrogen

[tex]M = N*m \\m=1.66*10^{-24}\\M=N*1.66*10^{-24}[/tex]

∴  

[tex]D[/tex] = [tex]\frac{N*1.66*10^{-24}}{V}[/tex]

[tex]\frac{V}{N*1.66*10^{-24}} = \frac{1}{ D}[/tex]

⇒ λ = [tex]\frac{1}{\sqrt{2}\pi d^{2}D  }[/tex]

⇒ λ = [tex]\frac{1.66*10^{-24}}{\sqrt{2}\pi (100*10^{-12})^{2}*1    }[/tex]

⇒ λ = [tex]0.0000373631 m[/tex]