In: Physics
Suppose that at least 19.6 eV is needed to free an electron from a particular element, i.e., to ionize the atom. What is the lowest frequency photon which can accomplish this? And, what is the corresponding wavelength for that photon? Give frequency for answer 1 and wavelength for answer 2.
The energy of the photon is,
E = hf
The minimum frequency for the photon is,
f = E/h
= [(19.6 eV)(1.6x10-19 J/ 1 eV)] / (6.63x10-34 J.s)
= 4.73x1015 Hz
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The wavelength of the photon is,
Wavelength = c / f
= [3x108 m/s] / [4.73x1015 Hz]
= 6.34x10-8 m
= 63.4x10-9 m
= 63.4 nm