. The Bell System technical journal . , which are fninuntly made aboutthe structure of the atom, usually refer imly lo these energs-values and the relations between them. The simplest question that can be asked aboiii ilie arrangement ofthe electrons is, whether they all occupy identical positions—being,for example, evenly distributed o\er the surface of a sphere or thecircumference of a circle, with the nucleus at its centre. If this istrue, the same amount of energy will be requiretl to remove any 158 soMr. . is Piivsrcs ii i5> electron from the atom as to remo\e a
. The Bell System technical journal . , which are fninuntly made aboutthe structure of the atom, usually refer imly lo these energs-values and the relations between them. The simplest question that can be asked aboiii ilie arrangement ofthe electrons is, whether they all occupy identical positions—being,for example, evenly distributed o\er the surface of a sphere or thecircumference of a circle, with the nucleus at its centre. If this istrue, the same amount of energy will be requiretl to remove any 158 soMr. . is Piivsrcs ii i5> electron from the atom as to remo\e any ollu-r. In the extremeopjxisite case there would be as many diflerenl amounts of energyrecjuiretl to remove an electron from the atom as there were , when radiation of a definite fre<iuency v falls upon a group ofatoms, any particular atom will cither ignore the radiation, or elsewill absorb a definite cjuantity of energy liv from it. (The letter /;,.1% denotes Plancks constant, ergs-seconds.) it. Fig. 1 follows that if an electron is extracted from an atom by this rtidiationand the work W required to extract it is not exactly as great as theamount liv, the difference will be turned over to the electron as kineticenergy-, and the speed v with which it departs from the atom willbe given by the equation and W can be determinetl by measuring v. We can convenientlyrefer to W as an extraction-energy or extraction-potential. Ifall the electrons occupy identical positions, W will be the same forall, and the emerging electrons will all have the same spctxl. If theyoccupy various p>ositions or levels as is more commonly said, there 160 BELL SYSTEM TECHNICAL JOURNAL will be as many different electron-speeds represented in the emergingelectron-stream as there are levels, and from these speeds the extrac-tion-energies characterizing (or indeed defining) the levels can bededuced. The apparatus in which the test is made is of the type shown inFig. 1.
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Keywords: ., bookcentury1900, bookdecade1920, booksubjecttechnology, bookyear1
