Potassium (39K) forms BCC crystal structure with crystal mass M=7kg and cube length \(a=4.5\times10^{-8} \ cm\) with one conduction electron per atom. The fermi energy at 0K is \(E_{0F}=3.6\ eV \). If isotopes of potassium (41K) is replaced by 39K then what will be new Fermi Energy at 0K is :
1
\(E_{0F}=3.4\ eV \)
2
\(E_{0F}=3.8\ eV \)
3
\(E_{0F}=3.6\ eV \)
4
None of the above