c
દ બ્રોગ્લી તરંગ લંબાઈ \(\lambda \,\, = \,\,\frac{h}{{\sqrt {3m{k_B}T} }},\,\) જ્યાં \(m\,  = \,\,\,\) હીલીયમ ના પરમાણુનું દળ

\( \Rightarrow \,\,m\,\, = \,\,\frac{{4\,\, \times \,{{10}^{ - 3}}kg}}{{6.023\,\, \times \,\,{{10}^{23}}}}\,\, = \,\,0.664\,\, \times \,\,{10^{ - 26}}kg\) અને

\(T\,\, = \,\,273\,\, + \,\,27 \, = \,\,300\,\,K\)

આથી\( \,\lambda \,\, = \,\, \frac{{6.63\,\, \times \,\,1{0^{ - 34}}}}{{\sqrt {3\,\,(0.664\,\, \times \,\,{{10}^{ - 26}})\,\,(1.38\,\, \times \,\,{{10}^{ - 23}})\,300} }}\)

\(m\, = \,\,7.3\,\, \times \,\,{10^{ - 11}}m\)

જો \(r\) એ મધ્યમાન  અંતર અને  \(V\)  આણીવ્ય  કદ  હોય તો , \(V\,  = \,\,{r^3}N\,\) અથવા

\(r \,{(V/N)^{1/3}}\) 

વાયુ ના એક અણુ માટે, \(PV\,  = \,\,RT \,\, \Rightarrow \,\,\,V\,\, = \,\,RT/\,P\)

આથી \(,\,r\, = \,\,{\left( {\frac{{RT/P}}{N}} \right)^{1/3}}\, = \,\,{\left( {\frac{{{k_B}T}}{P}} \right)^{1/3}}\,\)

\( \Rightarrow \,\,r\,\, = \,\,{\left( {\frac{{(1.38\,\, \times \,\,{{10}^{ - 23}})\,300}}{{1.01\,\, \times \,\,{{10}^5}}}} \right)^{1/3}}\,\, = \,\,3.4\,\, \times \,\,{10^{ - 9}}m\)

આથી \(\,\,\frac{r}{\lambda }\, = \,\,\frac{{3.4\,\, \times \,{{10}^{ - 9}}m}}{{7.3\,\, \times \,\,{{10}^{ - 11}}m}}\,\,\, \approx \,\,50\)

એટલે કે \(r\,\, = \,\,50\,\,\lambda \,,\,\,\,i.\,e.,\,\,\,\,r\,\, > \,\, > \,\,\lambda \)