Estimate for potassium, using Table 1, the value of the electron gas contribution to B. Table 1 Caleulated free electron Fermi surfue parameters for metals ai room temperature (Except for Na, K, Rb, 's at 5 K and Li at 78 K) Fermi temperature T,- ke in deg K Electron Radtus Fermi wavevector, in em- Fermi Fermi concentration, parameter Valency velocity, in em s energy, in eV Metal in em Li 4.70 x 10 1.11 x 10 0.92 3.25 1.29 x 10" 4.72 3.23 2. 12 5.48 x 10 3.75 2.46 Na 2.65 3.93 1.07 1.40 4.86 0.75 0.86 Rb 1.15 5.20 0.70 0.81 1.85 2. 15 Cs 0.91 5.63 0.64 0.75 1.58 1.83 8. 12 6.36 Cu 8.45 5.85 2.67 1.36 1.57 7.00 Ag Au 3.02 1.20 1.39 5.48 5.90 3.01 1.20 1.39 5.51 6.39 Be 24.2 1.88 1.93 2. 23 14. 14 16.41 Mg Ca Sr 8.60 2.65 1.37 1.58 7.13 8.27 4.60 3.27 1.11 1.28 4.68 5.43 3.56 3.56 1.02 1.18 3.95 4.58 Ba 3.20 3.69 0.98 1.13 3.65 4.24 Zn 13.10 2.31 1.57 1.82 9.39 10.90 Cd 9.28 2.59 1.40 1.62 7.46 8.66 3. Al 18.06 15.30 2.07 1.75 2.02 11.63 13.49 Ga 2.19 1.65 1.50 1.91 10.35 12.01 In 11.49 2.41 1.74 8.60 9.98 Pb 13.20 14.48 2.30 1.57 1.82 9.37 10.87 Sn(w) 2.23 1.62 1.88 10.03 11.64 The dimensionless radius parameter is defined as r,- ran, where an is the first Bohr radius and res the radius of a sphere that cntalna e alectroa