(a) Write the electron configuration for Li, and estimate the effective nuclear charge experienced by the valence electron.
(b) The energy of an electron in a one-electron atom or ion equals

Where Z is the nuclear charge and n is the principal quantum number of the electron. Estimate the first ionization energy of Li.
(c) Compare the result of your calculation with the value reported in Table 7.4 and explains the difference.
(d) What value of the effective nuclear charge gives the proper value for the ionization energy? Does this agree with your explanation in (c)?

(-2.18 io-181(S) TABLE 7.4Some Properties of the Alkali Metals Electron Configuration [He]2s1 [Ne]3s Melting Point (C) 181 98 63 39 28 Density (g/cm3) 0.53 0.97 0.86 1.53 1.88 Atomic Radius (A) 1.34 1.54 1.96 2.11 2.25 (kJ/mol) 520 496 Element Lithium Sodium Potassium [Ar]4s1 Rubidium [Kr]5.s Cesium 403 [Xe]6s 376