1216_Physics ProblemsTechnical Physics

1216_Physics ProblemsTechnical Physics - Chapter 43 P43.29...

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Chapter 43 557 P43.29 For sodium, M = 23 0 . g mol and ρ = 0971 . g c m 3 . (a) n N M e == × A 3 electrons mol g cm gmo l 602 10 23 0 23 .. . ej e j n e = × 2 54 10 2 54 10 22 28 electrons cm electrons m 33 (b) E h m n e F Js kg m J e V = F H G I K J F H G I K J = ×⋅ × × L N M M O Q P P = 2 23 34 2 31 28 3 19 2 3 8 6626 10 2 9 11 10 3 2 54 10 8 505 10 315 ππ . . . P43.30 The melting point of silver is 1 234 K. Its Fermi energy at 300 K is 5.48 eV. The approximate fraction of electrons excited is kT E B F JK K eV J eV = × × 138 10 1234 5 48 1 60 10 2% 23 19 . bg af . P43.31 Taking E F eV = 548 . for sodium at 800 K, fe e EE EE kT B B B =+ = =− = F F F 10 9 5 0 1 0950 0 5 2 6 00526 294 1 . . . ln . . −= × × F J 1.60 10 J eV eV 800 0203 23 19 . . . or E = 528 e V . P43.32 d = 100 . mm, so V = × −− 1 00 10 1 00 10 3 3 9 m m 3 . The density of states is gE CE m h
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This note was uploaded on 12/15/2011 for the course PHY 203 taught by Professor Staff during the Fall '11 term at Indiana State University .

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