Chemistry
Chemistry
4th Edition
ISBN: 9780393919370
Author: Thomas R. Gilbert
Publisher: NORTON
bartleby

Concept explainers

bartleby

Videos

Question
Book Icon
Chapter 7, Problem 7.45QP
Interpretation Introduction

Interpretation: The thin layers of potassium and sodium are given to be exposed to radiation of wavelength 300nm . The metal that emits electrons with the greater velocity is to be identified. Also the velocity of these electrons is to be calculated.

Concept introduction: Potassium and Sodium are the elements that are present in the periodic table. The velocity of an object tells the rate at which the object is moving with respect to time and position.

To determine: The velocity of the given electrons and the metal that emits electrons with the greater velocity.

Expert Solution & Answer
Check Mark

Answer to Problem 7.45QP

Solution

The velocity of electrons ejected by potassium is 8.04×105m/s_ .

The velocity of electrons ejected by sodium is 6.97×105m/s_ .

Thus, the potassium metal emits the electron with greater velocity.

Explanation of Solution

Explanation

Given

The radiation of wavelength, λ exposed to potassium and sodium is 300nm .

Work function for thin layer potassium, Φ is 3.68×1019J .

Work function for thin layer sodium, Φ is 4.41×1019J .

The energy of a photon is calculated by the formula,

E=hcλE=hv°=Φ (1)

Where,

  • Φ is the work function for elements.
  • E is the energy of a photon.
  • vο is the threshold frequency.
  • h is the Planck’s constant (6.62×1034Js) .
  • c is the velocity of light (3×108m/s) .

The wavelength in nm is converted into m given as,

300nm=300×109m

Substitute the value of wavelength, wavelength and velocity of light in equation (1).

E=6.62×1034×3×108300×109=6.62×1019J

As, E=hv therefore, hv=6.62×1019J

The work function for potassium, Φ=hv0 is 3.68×1019J .

The kinetic energy of an electron is calculated by the formula,

KE=hvhvο (2)

Substitute the value of hv and hvο in the equation (2).

KE=(6.62×10193.68×1019)J=2.94×1019J

The velocity is calculated by the formula,

v=2KEM (3)

Substitute the value of Kinetic energy and mass of an electron in equation (3).

v=2×2.94×10199.11×1031=5.88×10199.11×1031=0.5036×1012=8.04×105m/s_ (4)

Therefore, the velocity of electron emitted by potassium is 8.04×105m/s_ .

The work function for sodium, Φ=hv0 is 4.41×1019J .

The kinetic energy of an electron is calculated by the formula,

KE=hvhvο (5)

Substitute the value of hv and hvο in the equation (5).

KE=(6.62×10194.41×1019)J=2.21×1019J

The velocity is calculated by the formula,

v=2KEM (6)

Substitute the value of Kinetic energy and mass of an electron in equation (6).

v=2×2.21×10199.11×1031=4.42×10199.11×1031=0.485×1012=6.97×105m/s_ (7)

Thus, the velocity of electron emitted by sodium is 6.97×105m/s_ .

Therefore, on comparing the equation (4) and equation (7), it is concluded that electrons ejected from potassium element have greater velocity.

Conclusion

The velocity of electron emitted by potassium is 8.04×105m/s_ .

The velocity of electron emitted by sodium is 6.97×105m/s_ .

Thus, the velocity of electrons will be more in the case of potassium element.

Want to see more full solutions like this?

Subscribe now to access step-by-step solutions to millions of textbook problems written by subject matter experts!

Chapter 7 Solutions

Chemistry

Ch. 7.8 - Prob. 11PECh. 7.9 - Prob. 12PECh. 7.9 - Prob. 13PECh. 7.10 - Prob. 14PECh. 7 - Prob. 7.1VPCh. 7 - Prob. 7.2VPCh. 7 - Prob. 7.3VPCh. 7 - Prob. 7.4VPCh. 7 - Prob. 7.5VPCh. 7 - Prob. 7.6VPCh. 7 - Prob. 7.7VPCh. 7 - Prob. 7.8VPCh. 7 - Prob. 7.9VPCh. 7 - Prob. 7.10VPCh. 7 - Prob. 7.11VPCh. 7 - Prob. 7.12VPCh. 7 - Prob. 7.13VPCh. 7 - Prob. 7.14VPCh. 7 - Prob. 7.15VPCh. 7 - Prob. 7.16VPCh. 7 - Prob. 7.17VPCh. 7 - Prob. 7.18VPCh. 7 - Prob. 7.19VPCh. 7 - Prob. 7.20VPCh. 7 - Prob. 7.21QPCh. 7 - Prob. 7.22QPCh. 7 - Prob. 7.23QPCh. 7 - Prob. 7.24QPCh. 7 - Prob. 7.25QPCh. 7 - Prob. 7.26QPCh. 7 - Prob. 7.27QPCh. 7 - Prob. 7.28QPCh. 7 - Prob. 7.29QPCh. 7 - Prob. 7.30QPCh. 7 - Prob. 7.31QPCh. 7 - Prob. 7.32QPCh. 7 - Prob. 7.33QPCh. 7 - Prob. 7.34QPCh. 7 - Prob. 7.35QPCh. 7 - Prob. 7.36QPCh. 7 - Prob. 7.37QPCh. 7 - Prob. 7.38QPCh. 7 - Prob. 7.39QPCh. 7 - Prob. 7.40QPCh. 7 - Prob. 7.41QPCh. 7 - Prob. 7.42QPCh. 7 - Prob. 7.43QPCh. 7 - Prob. 7.44QPCh. 7 - Prob. 7.45QPCh. 7 - Prob. 7.46QPCh. 7 - Prob. 7.47QPCh. 7 - Prob. 7.48QPCh. 7 - Prob. 7.49QPCh. 7 - Prob. 7.50QPCh. 7 - Prob. 7.51QPCh. 7 - Prob. 7.52QPCh. 7 - Prob. 7.53QPCh. 7 - Prob. 7.54QPCh. 7 - Prob. 7.55QPCh. 7 - Prob. 7.56QPCh. 7 - Prob. 7.57QPCh. 7 - Prob. 7.58QPCh. 7 - Prob. 7.59QPCh. 7 - Prob. 7.60QPCh. 7 - Prob. 7.61QPCh. 7 - Prob. 7.62QPCh. 7 - Prob. 7.63QPCh. 7 - Prob. 7.64QPCh. 7 - Prob. 7.65QPCh. 7 - Prob. 7.66QPCh. 7 - Prob. 7.67QPCh. 7 - Prob. 7.68QPCh. 7 - Prob. 7.69QPCh. 7 - Prob. 7.70QPCh. 7 - Prob. 7.71QPCh. 7 - Prob. 7.72QPCh. 7 - Prob. 7.73QPCh. 7 - Prob. 7.74QPCh. 7 - Prob. 7.75QPCh. 7 - Prob. 7.76QPCh. 7 - Prob. 7.77QPCh. 7 - Prob. 7.78QPCh. 7 - Prob. 7.79QPCh. 7 - Prob. 7.80QPCh. 7 - Prob. 7.81QPCh. 7 - Prob. 7.82QPCh. 7 - Prob. 7.83QPCh. 7 - Prob. 7.84QPCh. 7 - Prob. 7.85QPCh. 7 - Prob. 7.86QPCh. 7 - Prob. 7.87QPCh. 7 - Prob. 7.88QPCh. 7 - Prob. 7.89QPCh. 7 - Prob. 7.90QPCh. 7 - Prob. 7.91QPCh. 7 - Prob. 7.92QPCh. 7 - Prob. 7.93QPCh. 7 - Prob. 7.94QPCh. 7 - Prob. 7.95QPCh. 7 - Prob. 7.96QPCh. 7 - Prob. 7.97QPCh. 7 - Prob. 7.98QPCh. 7 - Prob. 7.99QPCh. 7 - Prob. 7.100QPCh. 7 - Prob. 7.101QPCh. 7 - Prob. 7.102QPCh. 7 - Prob. 7.103QPCh. 7 - Prob. 7.104QPCh. 7 - Prob. 7.105QPCh. 7 - Prob. 7.106QPCh. 7 - Prob. 7.107QPCh. 7 - Prob. 7.108QPCh. 7 - Prob. 7.109QPCh. 7 - Prob. 7.110QPCh. 7 - Prob. 7.111QPCh. 7 - Prob. 7.112QPCh. 7 - Prob. 7.113QPCh. 7 - Prob. 7.114QPCh. 7 - Prob. 7.115QPCh. 7 - Prob. 7.116QPCh. 7 - Prob. 7.117QPCh. 7 - Prob. 7.118QPCh. 7 - Prob. 7.119QPCh. 7 - Prob. 7.120QPCh. 7 - Prob. 7.121QPCh. 7 - Prob. 7.122QPCh. 7 - Prob. 7.123QPCh. 7 - Prob. 7.124QPCh. 7 - Prob. 7.125QPCh. 7 - Prob. 7.126QPCh. 7 - Prob. 7.127QPCh. 7 - Prob. 7.128QPCh. 7 - Prob. 7.129APCh. 7 - Prob. 7.130APCh. 7 - Prob. 7.131APCh. 7 - Prob. 7.132APCh. 7 - Prob. 7.133APCh. 7 - Prob. 7.134APCh. 7 - Prob. 7.135APCh. 7 - Prob. 7.136APCh. 7 - Prob. 7.137APCh. 7 - Prob. 7.138APCh. 7 - Prob. 7.139APCh. 7 - Prob. 7.140APCh. 7 - Prob. 7.141APCh. 7 - Prob. 7.142APCh. 7 - Prob. 7.143APCh. 7 - Prob. 7.144APCh. 7 - Prob. 7.145APCh. 7 - Prob. 7.146APCh. 7 - Prob. 7.147APCh. 7 - Prob. 7.148AP
Knowledge Booster
Background pattern image
Chemistry
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, chemistry and related others by exploring similar questions and additional content below.
Recommended textbooks for you
Text book image
Chemistry
Chemistry
ISBN:9781305957404
Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Publisher:Cengage Learning
Text book image
Chemistry
Chemistry
ISBN:9781259911156
Author:Raymond Chang Dr., Jason Overby Professor
Publisher:McGraw-Hill Education
Text book image
Principles of Instrumental Analysis
Chemistry
ISBN:9781305577213
Author:Douglas A. Skoog, F. James Holler, Stanley R. Crouch
Publisher:Cengage Learning
Text book image
Organic Chemistry
Chemistry
ISBN:9780078021558
Author:Janice Gorzynski Smith Dr.
Publisher:McGraw-Hill Education
Text book image
Chemistry: Principles and Reactions
Chemistry
ISBN:9781305079373
Author:William L. Masterton, Cecile N. Hurley
Publisher:Cengage Learning
Text book image
Elementary Principles of Chemical Processes, Bind...
Chemistry
ISBN:9781118431221
Author:Richard M. Felder, Ronald W. Rousseau, Lisa G. Bullard
Publisher:WILEY
Quantum Mechanics - Part 1: Crash Course Physics #43; Author: CrashCourse;https://www.youtube.com/watch?v=7kb1VT0J3DE;License: Standard YouTube License, CC-BY