1. Energy Quantization and Wave-Particle Duality

(a) Einstein provided an explanation for the observation of a wavelength threshold for the emission of electrons when a metal is illuminated by visible light. What concept did he invoke in his explanation?

Concept

light cannst like particles.

(b) Atoms were found to emit and absorb light of only certain, discrete wavelengths. What concept did Bohr invoke to explain this observation?

Concept

ms can exist with ould certain Values of the energy

(c) In the Franck-Hertz experiment, electrons of variable energy collide with lithium atoms. The first excitation threshold occurs at 1.85 eV. Compute the wavelength of light corresponding to this threshold.

6.63×10-34Js

E (1.85cV) (1.609×10-19JcV1)