Photo Electric Effect On Molybdenum
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Photo Electric Effect On Molybdenum

The photoelectric effect is the emission of electrons from metal surfaces by light.
Molybdenum metal must absorb radiation with a minimum frequency of 1.09 x 1015 /s before it can emit an electron from its surface as a result of the photoelectric effect.
(a) What is the minimum energy needed to produce this effect?
(b) What wavelength radiation will provide a photon for this energy?
(c) If molybdenum is irradiated with light of wavelength of 120 nm, what is the maximum possible kinetic energy of the emitted electrons?

The strings: S7P3A32 (force - push)

The math:
The Pj problem of interest is of type force (force - push)

(a) Frequency, ν = 1.09 x 1015/s
Planck's constant = 6.626 x 10-34 Joules-s
So, energy E = hν = 6.626 x 10-34 x 1.09 x 1015 = 7.22 x 10-19 Joule.

(b) Wavelength, λ = c/ν (where c is the velocity of light)
So, λ = (3 x 108)/(1.09 x 1015) = 2.75 x 10-7 = 275 x 10-9 = 275 nm.

(c) E120 - E275 = hc(1/120 - 1/275) x 109 = hc x 109(0.0083 - 0.0036)
So, E120 - E275 = 0.0047 x 6.626 x 10-34 x 3 x 108 x 109 = 9.3 x 10-19 J/electron.

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