HARDMCQ SINGLEJEE Mains ChemistryPhysical ChemistryAtomic StructureIntro
A photon of 300 nm is absorbed by a gas and then re-emits two photons. One re-emitted photon has wavelength 496 nm. The wavelength of the second re-emitted photon is
0.757 nm
1.857 nm
2.957 nm
3.657 nm
Explanation
By conservation of energy: 1/λ₁ = 1/λ₂ + 1/λ₃. 1/λ₃ = 1/300 − 1/496 = (496−300)/(300×496) = 196/148800. λ₃ = 148800/196 ≈ 759 nm ≈ 757 nm
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