The first line of the Lyman series of hydrogen ( ) is isolated from a discharge lamp…
PHYSICS · Multi-part · Fermi University Physics · Quantum Mechanics · Origins of quantum theory · Origins of quantum theory
Quantum Mechanics: From the Photon to the Hydrogen Atom, Ch Line spectra, the Bohr atom and the old quantum theory
Problem
The first line of the Lyman series of hydrogen (n2=2→n1=1) is isolated from a discharge lamp and shone on the clean tungsten cathode of an evacuated photoelectric cell. The work function of tungsten is W=4.55 eV. Each photoelectron is ejected by absorbing one photon, and Kmax refers to the electrons that reach the surface without losing energy inside the metal. Take the Rydberg constant as RH=1.097×107m−1 and hc=1240 eV nm.
((a)) Find the wavelength of the line, in nm.
((b)) Find the maximum kinetic energy of the photoelectrons, in eV.
((c)) Find the stopping potential of the cell, in volts.