Respuesta :
Answer:
(a) No overlap
(b) There is overlap
(c) Two
(d) See explanation below
Explanation:
1/Ī» = Rh (1/nā² - 1/nā² )
where Ī» is the wavelength of the transion, nā and nā are the principal energy levels ( nā < nā )
To solve this question, our strategy is to :
1. Calculate the longest wavelength for nā = 1, Ā which Ā corresponds to Ā the transition with nā = 2.
2. Calculate the Ā shortest wavelength for nā = 2, which Ā corresponds to nā = infinity.
3. Compare the values to check if there is overlap
Lets plug the numbers to visualize this better:
Rydberg“s equation : 1/λ = 1.097 x 10ⷠ/m x  (1/nⲠ- 1/nⲠ)
For nā = 1, longest wavelength ( nā = 2 ) :
1/λ = 1.097 x 10ⷠ/m x  (1/1 ² - 1/2² ) = 8227.5/m
Ī» Ā = 1/8227.5/m = 121 x 10ā»ā“ m x 1 x 10ā¹ nm/m = 1.22 x 10² nm
For nā = 2, shortest wavelength ( nā = infinity ) :
1/λ = 1.097 x 10ⷠ/m x  (1/2 ² ) = 2.7 x 10ⶠ/m
Ī» Ā = 1/2.7 x 10ā¶/m = 3.7 x 10ā»ā· m x 1 x 10ā¹ nm/m = 3.70 x 10² nm
There is no overlap between the nā = 1 and nā = 2 series ( there is no overlap Ā Ā 1.22 x 10² nm vs 3.70 x 10² nm )
(b) Ā Repeat the same Ā procedure as in part (a)
For nā = 3, longest wavelength ( nā = 4 ) :
1/Ī» = 1.097 x 10ā· /m x Ā (1/3 ² - 1/4² ) =5.33 x 10āµ/m
Ī» Ā = 1/5.33 x 10āµ/m =1.88 x 10ā»ā¶ m x 1 x 10ā¹ nm/m = 1.88 x 10³ nm
For nā = 4, shortest wavelength ( nā = infinity ) :
1/λ = 1.097 x 10ⷠ/m x  (1/4 ² ) = 6.86 x 10ⵠ/m
Ī» Ā = 1/6.86 x 10āµ/m = 1.46 x10ā»ā¶ m x 1 x 10ā¹ nm/m = 1.46 x 10³ nm
There will be overlap
(c) Proceed as in the calculations above but now not only calculate for nā = 5 for nā = 4 but also a couple more and Ā verify if there is overlap and count them.
For nā = 4 Ā lets calculate nā = 5, 6, 7
1/Ī» = Ā 1.097 x 10ā· /m x Ā (1/4 ² - 1/5² ) = 2.47 x 10āµ/m
Ī» Ā = 1/2.47 x 10āµ/m = 4.05 x10ā»ā¶ m x 1 x 10ā¹ nm/m = 4.05 x 10³ nm
The same calculation is done for nā = 6 and 7, with the following results:
2.63 x 10³ nm, 2.17 x 10³ nm
Now the shortest wavelength in nā = 5 is:
1/λ = 1.097 x 10ⷠ/m x  (1/5² ) = 4.39 x 10ⵠ/ m
Ī» Ā = 1/4.39 x 10āµ/m = 2.28 x10ā»ā¶ m x 1 x 10ā¹ nm/m = 2.28 x 10³ nm
There will be an overlap with 2 lines of nā = 4 (2.63 x 10³ nm, 2.17 x 10³ nm )
(d) The overlap tell Ā us that the energy gap between energy levels becomes smaller as we could see from the calculations above. The spectra becomes confusing Ā as there is more overlaps.