EXERCISE Repeat the problem for an excited state of doubly-ionized lithium (Z = 3, n = 9). E2= eV r2 = HINTS: GETTING STARTED nm I I'M STUCK!

College Physics
11th Edition
ISBN:9781305952300
Author:Raymond A. Serway, Chris Vuille
Publisher:Raymond A. Serway, Chris Vuille
Chapter1: Units, Trigonometry. And Vectors
Section: Chapter Questions
Problem 1CQ: Estimate the order of magnitude of the length, in meters, of each of the following; (a) a mouse, (b)...
icon
Related questions
Question
100%
GOAL Apply the modified Bohr theory to a hydrogen-like atom.
PROBLEM Singly ionized helium, He a hydrogen-like system, has one electron in the 1s orbit when
the atom is in its ground state. Find (a) the energy of the system in the ground state in electron volts
and (b) the radius of the ground state orbit.
STRATEGY Part (a) requires substitution into the modified Bohr model. In part (b) modify the equation
for the radius of the Bohr orbits by replacing e2 by Ze2, where Z is the number of protons in the nucleus.
SOLUTION
(A) Find the energy of the system in the ground state.
Write the equation for the energies of a
hydrogen-like system:
Substitute the constants and convert to
electron volts:
Substitute Z = 2 (the atomic number
of helium) and n = 1 to obtain the
ground state energy:
(B) Find the radius of the ground state.
Generalize to a hydrogen-like atom by
substituting Ze2 for e²:
For our case, n = 1 and Z = 2.
En
En
rn
m.X.2²2²2² (²2)
mk 4
2h²
E₁ = 4(13.6 eV) = -54.4 eV
"1
z²(13.6 eV)
2
n²h²
mk Ze²
=
n²
Z
= 0.0265 nm
-(ao)
n²
(0.0529 nm)
LEARN MORE
REMARKS Notice that for higher Z, the energy of a hydrogen-like atom is lower, which means that the
electron is more tightly bound than in hydrogen. The result is a smaller atom, as seen in part (b).
QUESTION When an electron undergoes a transition from a higher to lower state in singly ionized
helium, how will the energy of the emitted photon compare with the analogous transition in hydrogen?
Explain. (Select all that apply.)
The transition energy will be higher in singly ionized helium.
Transcribed Image Text:GOAL Apply the modified Bohr theory to a hydrogen-like atom. PROBLEM Singly ionized helium, He a hydrogen-like system, has one electron in the 1s orbit when the atom is in its ground state. Find (a) the energy of the system in the ground state in electron volts and (b) the radius of the ground state orbit. STRATEGY Part (a) requires substitution into the modified Bohr model. In part (b) modify the equation for the radius of the Bohr orbits by replacing e2 by Ze2, where Z is the number of protons in the nucleus. SOLUTION (A) Find the energy of the system in the ground state. Write the equation for the energies of a hydrogen-like system: Substitute the constants and convert to electron volts: Substitute Z = 2 (the atomic number of helium) and n = 1 to obtain the ground state energy: (B) Find the radius of the ground state. Generalize to a hydrogen-like atom by substituting Ze2 for e²: For our case, n = 1 and Z = 2. En En rn m.X.2²2²2² (²2) mk 4 2h² E₁ = 4(13.6 eV) = -54.4 eV "1 z²(13.6 eV) 2 n²h² mk Ze² = n² Z = 0.0265 nm -(ao) n² (0.0529 nm) LEARN MORE REMARKS Notice that for higher Z, the energy of a hydrogen-like atom is lower, which means that the electron is more tightly bound than in hydrogen. The result is a smaller atom, as seen in part (b). QUESTION When an electron undergoes a transition from a higher to lower state in singly ionized helium, how will the energy of the emitted photon compare with the analogous transition in hydrogen? Explain. (Select all that apply.) The transition energy will be higher in singly ionized helium.
REMARKS Notice that for higher Z, the energy of a hydrogen-like atom is lower, which means that the
electron is more tightly bound than in hydrogen. The result is a smaller atom, as seen in part (b).
QUESTION When an electron undergoes a transition from a higher to lower state in singly ionized
helium, how will the energy of the emitted photon compare with the analogous transition in hydrogen?
Explain. (Select all that apply.)
The transition energy will be higher in singly ionized helium.
This happens because the helium atom has more protons.
This happens because the helium nucleus is less massive.
The transition energy will be lower in singly ionized helium.
This happens because the helium atom has more neutrons.
EXERCISE
Repeat the problem for an excited state of doubly-ionized lithium (Z = 3, n = 9).
eV
E2
r2
nm
HINTS: GETTING STARTED
I'M STUCK!
Transcribed Image Text:REMARKS Notice that for higher Z, the energy of a hydrogen-like atom is lower, which means that the electron is more tightly bound than in hydrogen. The result is a smaller atom, as seen in part (b). QUESTION When an electron undergoes a transition from a higher to lower state in singly ionized helium, how will the energy of the emitted photon compare with the analogous transition in hydrogen? Explain. (Select all that apply.) The transition energy will be higher in singly ionized helium. This happens because the helium atom has more protons. This happens because the helium nucleus is less massive. The transition energy will be lower in singly ionized helium. This happens because the helium atom has more neutrons. EXERCISE Repeat the problem for an excited state of doubly-ionized lithium (Z = 3, n = 9). eV E2 r2 nm HINTS: GETTING STARTED I'M STUCK!
Expert Solution
steps

Step by step

Solved in 2 steps

Blurred answer
Knowledge Booster
Emission and absorption
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, physics and related others by exploring similar questions and additional content below.
Similar questions
  • SEE MORE QUESTIONS
Recommended textbooks for you
College Physics
College Physics
Physics
ISBN:
9781305952300
Author:
Raymond A. Serway, Chris Vuille
Publisher:
Cengage Learning
University Physics (14th Edition)
University Physics (14th Edition)
Physics
ISBN:
9780133969290
Author:
Hugh D. Young, Roger A. Freedman
Publisher:
PEARSON
Introduction To Quantum Mechanics
Introduction To Quantum Mechanics
Physics
ISBN:
9781107189638
Author:
Griffiths, David J., Schroeter, Darrell F.
Publisher:
Cambridge University Press
Physics for Scientists and Engineers
Physics for Scientists and Engineers
Physics
ISBN:
9781337553278
Author:
Raymond A. Serway, John W. Jewett
Publisher:
Cengage Learning
Lecture- Tutorials for Introductory Astronomy
Lecture- Tutorials for Introductory Astronomy
Physics
ISBN:
9780321820464
Author:
Edward E. Prather, Tim P. Slater, Jeff P. Adams, Gina Brissenden
Publisher:
Addison-Wesley
College Physics: A Strategic Approach (4th Editio…
College Physics: A Strategic Approach (4th Editio…
Physics
ISBN:
9780134609034
Author:
Randall D. Knight (Professor Emeritus), Brian Jones, Stuart Field
Publisher:
PEARSON