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PHXII12:ATOMS

356381 What percentage increase in wavelength leads to $75 %$ loss of photon energy in a photon-electron collision?

200 %

100 %

67.7 %

300 %

Energy of photon, $\frac{h c}{λ}$
Energy left $E = 0.25 E = \frac{h c}{4 λ}$
$%$ change in wavelength $= \frac{4 λ - λ}{λ} \times 100 %$
$= 300 %$