Skip to main content
Ch.6 - Electronic Structure of Atoms
Chapter 6, Problem 91b

The series of emission lines of the hydrogen atom for which nf = 3 is called the Paschen series. (b) Calculate the wavelengths of the first three lines in the Paschen series—those for which ni = 4, 5, and 6.

Verified step by step guidance
1
Identify the formula to use for calculating the wavelengths of the emission lines in the hydrogen atom. The Rydberg formula is appropriate here: \( \frac{1}{\lambda} = R_H \left( \frac{1}{n_f^2} - \frac{1}{n_i^2} \right) \), where \( \lambda \) is the wavelength, \( R_H \) is the Rydberg constant (approximately 1.097 x 10^7 m^-1), \( n_f \) is the final energy level, and \( n_i \) is the initial energy level.
Set \( n_f = 3 \) for the Paschen series as given in the problem statement.
Calculate the wavelength for the first line in the series where \( n_i = 4 \). Plug these values into the Rydberg formula and solve for \( \lambda \).
Repeat the calculation for the second line where \( n_i = 5 \). Again, use the Rydberg formula with these values to find \( \lambda \).
Calculate the wavelength for the third line where \( n_i = 6 \) using the same method.

Verified Solution

Video duration:
7m
This video solution was recommended by our tutors as helpful for the problem above.
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Emission Spectra

Emission spectra are produced when electrons in an atom transition from a higher energy level to a lower one, releasing energy in the form of light. Each transition corresponds to a specific wavelength, resulting in distinct lines in the spectrum. For hydrogen, these lines are categorized into series based on the final energy level of the electron, such as the Paschen series, which ends at n=3.
Recommended video:
Guided course
01:51
Emission Spectra

Rydberg Formula

The Rydberg formula is used to calculate the wavelengths of spectral lines in hydrogen and other hydrogen-like atoms. It is expressed as 1/λ = R_H (1/n_f^2 - 1/n_i^2), where λ is the wavelength, R_H is the Rydberg constant, n_f is the final energy level, and n_i is the initial energy level. This formula allows for the determination of wavelengths for transitions between specific energy levels.
Recommended video:
Guided course
02:26
Skeletal Formula

Quantum Energy Levels

Quantum energy levels refer to the discrete energy states that electrons can occupy in an atom. In hydrogen, these levels are denoted by principal quantum numbers (n), where n=1 is the ground state and higher numbers represent excited states. The differences in energy between these levels dictate the wavelengths of light emitted during electron transitions, forming the basis for the observed emission spectra.
Recommended video:
Guided course
02:55
Principal Quantum Number
Related Practice
Textbook Question

Consider a transition in which the electron of a hydrogen atom is excited from n = 1 to n = . (d) How are the results of parts (b) and (c) related to the plot shown in Exercise 6.88?

558
views
Textbook Question

The human retina has three types of receptor cones, each sensitive to a different range of wavelengths of visible light, as shown in this figure (the colors are merely to differentiate the three curves from one another; they do not indicate the actual colors represented by each curve):

(c) Explain why the sky appears blue even though all wavelengths of solar light are scattered by the atmosphere.

548
views
Textbook Question

The series of emission lines of the hydrogen atom for which nf = 3 is called the Paschen series. (a) Determine the region of the electromagnetic spectrum in which the lines of the Paschen series are observed.

757
views
Textbook Question

Determine whether each of the following sets of quantum numbers for the hydrogen atom are valid. If a set is not valid, indicate which of the quantum numbers has a value that is not valid: (e) n = 2, l = 1, ml = 1, ms = -12

1452
views
Textbook Question

Bohr's model can be used for hydrogen-like ions—ions that have only one electron, such as He+ and Li2+. (a) Why is the Bohr model applicable to He+ ions but not to neutral He atoms?

2032
views
Open Question
An electron is accelerated through an electric potential to a kinetic energy of 1.6 * 10^-15 J. What is its characteristic wavelength? [Hint: Recall that the kinetic energy of a moving object is E = 1/2 mv^2, where m is the mass of the object and v is the speed of the object.]