Ch.7 - Quantum MechanicsSee all chapters
All Chapters
Ch.1 - Intro to General Chemistry
Ch.2 - Atoms & Elements
Ch.3 - Chemical Reactions
BONUS: Lab Techniques and Procedures
BONUS: Mathematical Operations and Functions
Ch.4 - Chemical Quantities & Aqueous Reactions
Ch.5 - Gases
Ch.6 - Thermochemistry
Ch.7 - Quantum Mechanics
Ch.8 - Periodic Properties of the Elements
Ch.9 - Bonding & Molecular Structure
Ch.10 - Molecular Shapes & Valence Bond Theory
Ch.11 - Liquids, Solids & Intermolecular Forces
Ch.12 - Solutions
Ch.13 - Chemical Kinetics
Ch.14 - Chemical Equilibrium
Ch.15 - Acid and Base Equilibrium
Ch.16 - Aqueous Equilibrium
Ch. 17 - Chemical Thermodynamics
Ch.18 - Electrochemistry
Ch.19 - Nuclear Chemistry
Ch.20 - Organic Chemistry
Ch.22 - Chemistry of the Nonmetals
Ch.23 - Transition Metals and Coordination Compounds

Heisenberg's Uncertainty Principle tries to explain the potential duality of an electron behaving as either a particle or wave. 

Heisenberg's Uncertainty Principle

Heisenberg's Uncertainty Principle illustrates that an electron can behave as a particle or as a wave, but never both simultaneously. 

Concept #1: The duality of an electron. 

Concept #2: To illustrate this dual nature of an electron Heisenberg created his Uncertainty or Indeterminacy Principle 

Example #1: An electron has an uncertainty in its position of 630 pm. What is the uncertainty in its velocity? 

Additional Problems
An electron has an uncertainty in its position of 552 pm. What is the uncertainty in its velocity?
An electron traveling at 3.7 x 10 5 m/s has an uncertainty in its velocity of 1.88 x 10 5 m/s. What is the uncertainty in its position.
According to the Heisenberg uncertainity principle , if the uncertainity in the speed of an electron is 3.5 x 103 m/s, the uncertainity in its position (in m) is at least: A) 66 m  B) 1.7 x 10-8 m C) 17 m D) 2.1 x 10-10 m E) 6.6 x 10-8 m
According to the Heisenberg uncertainty principle, if the uncertainty in the speed of an electron is 3.5 x 103 m/s, the uncertainty in its position (in m) is at least (mass electron = 9.11 x 10-31 kg) __. A) 1.7 x 10-8 m B) 6.6 x 10-8 m C) 17 m D) 66 m E) None of these choices is correct
An alpha particle with mass = 6.6 x 10  −24 g moves at a speed of 1.52 x 10 7 ± 0.03 m/s. What is the minimum uncertainty of its position? a) 2.66 x 10 −10 m b) 2.66 x 10 −7 m c) 6.54 x 10 −3 m d) 8.54 x 10 −3 m e) 1.75 x 12 −5 m
According to the Heisenberg uncertainty principle, if the uncertainty in the speed of an electron is 3.5 x 103 m/s, the uncertainty in its position (in m) is at least. 66 m   17 m   6.6 x 10-8 m   1.7 x 10-8 m   2.1 x 10-10 m
An electron has an uncertainty in its position of 190 pm. What is its uncertainty in its velocity? 272 x 103 m/s   1.12 x 105 m/s   521 x 105 m/s   4.21 x 102 m/s   305 x 103 m/s
Why does the uncertainty principle make it impossible to predict a trajectory for the electron?a. Because you cannot know both the position and velocity of the electron simultaneously.b. Because you cannot know both the position and force acting on the electron simultaneously.c. Because you cannot know the velocity of the electron.d. Because you cannot know the force acting on the electron.e. Because you cannot know both the velocity and force acting on the electron simultaneously.f. Because you cannot know the position of the electron.
Using Heisenberg’s uncertainty principle, calculate the uncertainty in the position of (a) a 1.50-mg mosquito moving at a speed of 1.40 m/s if the speed is known to within ∓0.01 m/s
Using Heisenberg’s uncertainty principle, calculate the uncertainty in the position of (b) a proton moving at a speed of (5.00 ∓ 0.01) x 104 m/s. 
Calculate the uncertainty in the position of (a) an electron moving at a speed of (3.00 ∓ 0.01) x 105 m/s
Calculate the uncertainty in the position of (b) a neutron moving at this same speed. (The masses of an electron and a neutron are given in the table of fundamental constants)
Calculate the uncertainty in the position of (a) an electron moving at a speed of (3.00 ∓ 0.01) x 105 m/s, (b) a neutron moving at this same speed. (The masses of an electron and a neutron are given in the table of fundamental constants in the inside cover of the text.) (c)What are the implications of these calculations to our model of the atom?
To what uncertainty (in m) can the position of a baseball traveling at 45.0 m/s be measured if the uncertainty of its speed is 0.10%? The mass of a baseball is about 0.145 kg. a. 8.1 x 10-33 m b. 5.6 x 10-15 m c. 6.7 x 10-45 m d. 5.9 x 10-14 m e. 4.4 x 10-65 m
A student is examining a bacterium under the microscope. The E. coli bacterial cell has a mass of = 0.500 (where a femtogram,fg , is 10-15 g) and is swimming at a velocity of v = 9.00 um/s, with an uncertainty in the velocity of 8.00 %. E. coli bacterial cells are around 1 um (10-6m ) in length. The student is supposed to observe the bacterium and make a drawing. However, the student, having just learned about the Heisenberg uncertainty principle in physics class, complains that she cannot make the drawing. She claims that the uncertainty of the bacterium's position is greater than the microscope's viewing field, and the bacterium is thus impossible to locate.What is the uncertainty of the position of the bacterium? Express your answer numerically in meters.