The decreasing order of wavelengths of the photons emitted or absorbed by the H atom is : b → c → a → d
Rydberg's formula :
,
where λ is the wavelength of the photon emitted or absorbed from an H atom electron transition from to
and
= 109677 is the Rydberg Constant. Here
and
represents the transitions.
(a) =2 to
= infinity
= 109677/4 [since 1/infinity = 0] Therefore,
= 4 / 109677 = 0.00003647 m
(b) =4 to
= 20
= 6580.62
Therefore, = 1 / 6580.62 = 0.000152 m
(c) =3 to
= 10
= 11089.56
Therefore, = 1 / 11089.56 = 0.00009 m
(d) =2 to
= 1
= - 82257.75
Therefore, = 1 /82257.75 = - 0.0000121 m
[Even though there is a negative sign, the magnitude is only considered because the sign denotes that energy is emitted.]
So the decreasing order of wavelength of the photon absorbed or emitted is b → c → a → d.
Learn more about the Rydberg's formula athttps://brainly.com/question/14649374
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