(a)
Interpretation:
The two expressions for Doppler broadening and Doppler half-width needs to be shown equivalent to each other.
Concept introduction:
The equation for the half-width for Doppler broadening Δλ0 of an atomic line can be used to study line broadening in a low − pressure laser-induced plasma.
Explanation of Solution
The change in wavelength at the center of the emission line can be represented as follows:
Here,
Similarly, the Doppler half-width can be calculated as follows:
Here,
Also,
(b)
Interpretation:
The half-width for Doppler broadening needs to be determined for 4s to 4p transition for nickel atom.
Concept introduction:
Doppler bordering is happened due to the Doppler effect caused by a distribution of velocities of atomic molecules.
Answer to Problem 8.12QAP
The half-width = 7934 nm and
Explanation of Solution
Given information:
Calculation:
The Doppler half-width can be calculated as follows:
(c)
Interpretation:
The natural line width for the above transition needs to be determined, assuming that the lifetime of the excited state is
Concept introduction:
Natural line width is associated with the decay time (Natural life-time) and it is a minimum line width that does not contain effects such as collisional and Doppler broadening.
Answer to Problem 8.12QAP
Natural line width =
Explanation of Solution
Natural line width can be calculated as follows:
Putting the values,
(d)
Interpretation:
To show that the relativistic expression is consistent with the mentioned equation given for the low atomic speeds.
Concept introduction:
When compared with the
Explanation of Solution
When the atomic speed very low V is considerably small when compared to the c, that of the speed of light. Hence the above mentioned equation could be written as shown below. Hence, at low velocities, relativistic kinetic energy reduces to classical kinetic energy. No object with mass can achieve the speed of light because an infinite amount of energy input and an infinite amount of work is required to accelerate a mass to the speed of light.
(e)
Interpretation:
The speed of an iron atom the 4s to 4p transition at 385.9911 nm should be determined.
Concept introduction:
The rest wavelength of Nickel is 410 nm. The formula used is:
Answer to Problem 8.12QAP
Explanation of Solution
Given information:
Calculation:
(f)
Interpretation:
The fraction of a sample of iron atoms at 10,000 K that would have the velocity calculated in part e should be computed.
Concept introduction:
Natural line width is associated with the decay time. It is a minimum line width that does not contain effects such as collisional and Doppler broadening.
Answer to Problem 8.12QAP
Explanation of Solution
Given information:
Calculation:
(g)
Interpretation:
A spreadsheet should be created to calculate the Doppler half-width
Concept introduction:
Doppler bordering is happened due to the Doppler effect caused by a distribution of velocities of atomic molecules.
Answer to Problem 8.12QAP
Refer the spreadsheet
Explanation of Solution
Given information:
Calculation:
(h)
Interpretation:
The four sources of pressure broadening should be listed by consulting the paper by Gornushkin et al. (note 10).
Explanation of Solution
The interaction of the surrounding particles with the radiating atom is the major source of pressure line broadening, which causes a phase shift and a frequency disturbance.
The most important cases of interaction are:
- linear Starkeffect, p = 2;
- resonance interaction between identical particles, p = 3;
- quadratic Stark effect, p = 4,
- van der Waals interaction, p = 6.
The superposition problems are avoided by two approximations:
- ‘nearest neighbor approximation’, in this the considered interaction is interaction with the closest perturber.
- The impact or collision concept, in which moving perturbers act sequentially in time.
Want to see more full solutions like this?
Chapter 8 Solutions
Principles of Instrumental Analysis
- In high-temperature sources, sodium atoms emit a doublet with an average wavelength of 1139 nm. The transition responsible is from the 4s to 3p state. Set up a spreadsheet to calculate the ratio of the numberof excited atoms in the 4s state to the number in the ground 3s state over the temperature range from anacetylene-oxygen flame (3000°C) to the hottest part of an inductively coupled plasma source (8750°C).arrow_forwardA 5.00 mm cell was filled with a solution of a dye. The concentration of the dye was 18.5 mmol dm−3. Calculate the molar absorption coefficient of the dye at this wavelength given that the transmission was 29 per cent. What will the transmittance be through a 2.50 mm cell at the same wavelength?arrow_forward(b) Calculate the half width in nanometers for Doppler broadening of the 4s S 4p transition for atomic nickel at 361.939 nm (3619.39 Å) at a temperature of 20,000 K in both wavelength and frequency units. (c) Estimate the natural line width for the transition in (b) assuming that the lifetime of the excited state is 5*10^(-8) s.arrow_forward
- What is the Doppler-shifted wavelength of a red (680 nm) traffic light approached at 60 km h−1?arrow_forwardIn an X-ray photoelectron experiment. a photon of wavelength 100 pm ejects an electron from the inner shell of an atom and it emerges with a speed of 2.34 x 104 km s-1. Calculate the binding energy of the electron.arrow_forwardThe spacing of lines in the microwave spectrum of 27Al1H is 12.604 cm−1; calculate the moment of inertia and bond length of the molecule.arrow_forward
- What is the wavenumber of the radiation emitted when a hydrogen atom makes a transition corresponding to a change in energy of 10.20 eV?arrow_forwardA 2.0 mm cell was filled with a solution of benzene in a non-absorbing solvent. The concentration of the benzene was 0.010 mol dm−3 and the wavelength of the radiation was 256 nm (where there is a maximum in the absorption). Calculate the molar absorption coefficient of benzene at this wavelength given that the transmission was 48 per cent. What will the transmittance be through a 4.0 mm cell at the same wavelength?arrow_forward
- Principles of Modern ChemistryChemistryISBN:9781305079113Author:David W. Oxtoby, H. Pat Gillis, Laurie J. ButlerPublisher:Cengage LearningPrinciples of Instrumental AnalysisChemistryISBN:9781305577213Author:Douglas A. Skoog, F. James Holler, Stanley R. CrouchPublisher:Cengage Learning