= James Franck
{c}
{tag=Physicist}
{title2=1882–1964}
= J. Franck
{c}
{synonym}
<James Franck> and <Gustav Ludwig Hertz> measured the transfer of <kinetic energy> from free <electrons> into atomic excitation. In <Mercury> vapor, the collected <electric current> changes repeatedly as the accelerating <voltage> rises. Below an excitation threshold, an <electron> cannot excite the relevant atomic <quantum state>; above it, an <inelastic collision> can remove a characteristic <energy>. Repeated acceleration and energy loss produce the successive features, linking the <Franck-Hertz experiment> to quantized atomic structure.<Über Zusammenstöße zwischen Elektronen und den Molekülen des Quecksilberdampfes und die Ionisierungsspannung desselben by James Franck and Gustav Ludwig Hertz>[Mercury-vapor electron-impact measurements]{ref}<Nobel Lectures, Physics 1922–1941/Transformations of Kinetic Energy of Free Electrons into Excitation Energy of Atoms by Impacts by James Franck>[Nobel lecture: interpretation of excitation-energy transfer]{ref}
Physics.https://www.lib.uchicago.edu/collex/exhibits/university-chicago-centennial-catalogues/university-chicago-faculty-centennial-view/james-franck-1882-1964-physical-chemistry/[Independent professional profile]{ref}
\Image[https://upload.wikimedia.org/wikipedia/commons/6/6c/James_Franck.jpg]
{title=Portrait of <James Franck>}
{width=240}
Back to article page
