From the previous post "Most Penetrating X ray, Boron" dated 20 Jan 2018,
\(A_x=1.1974*16.78*10^{-9}*\cfrac{0.1}{3.710}=5.41\text{e-10}\)
If we assume that this is due to a particle of radius \(a_{\psi}\) we have,
\(a^2_{\psi}=\cfrac{A_x}{\pi}=1.7239\text{e-10}\,m\)
\(a_{\psi}=1.313\text{e-5}\,m\)
This could be the size of the electron cloud of a copper atom.
This is wrong because a length \(0.1\,m\) was used, it should be,
\(A_x=1.1974*16.78*10^{-9}*\cfrac{1}{0.371}=5.41\text{e-8}\)
where a length of \(1\,m\) is used,
\(a_{\psi}=1.313\text{e-4}\,m\)
This is the effective size of the electric field around a copper atom and not the radius of the electron orbits around the nucleus, in the electron cloud.
