Chapter 15, More on the models of the atom Video Solutions, Physics in Focus HSC Course

01:19

Problem 1

Define wave-particle duality.

Dr. Satish Ingale

Numerade Educator

02:56

Problem 2

Explain the meaning of matter waves.

Ren Jie Tuieng

Numerade Educator

02:07

(a) Calculate the wavelength of the matter wave when a tennis ball with a mass of $20.0 \mathrm{~g}$ is moving at a velocity of $2.00 \mathrm{~m} \mathrm{~s}^{-1}$.
(b) Calculate the wavelength of the matter wave when a proton is made to move at a velocity of $3.00 \mathrm{~km} \mathrm{~s}^{-1}$.
(c) Calculate the frequency of the matter wave when a neutron is made to move at $53.6 \times 10^3 \mathrm{~m} \mathrm{~s}^{-1}$.

Karthik Chinni

Numerade Educator

09:50

Problem 4

When an electron is accelerated by a voltage, it achieves a high velocity such as in the case of a cathode ray tube (CRT) (see figure).
(a) Demonstrate, by drawing on the diagram, the direction in which the electron moves in the CRT.
(b) What is the wavelength of the matter wave of the electron when the voltage is set at $32.0 \mathrm{~V}$ ?
(c) What is the required voltage to produce an electron wave with a wavelength of $1.32 \times 10^{-10} \mathrm{~m} ?$

Sheh Lit Chang

University of Washington

08:43

Problem 5

Electron microscopes are devices that use the wave characteristics of electrons to produce magnified pictures of minute objects.
(a) One of the steps in the operation of an electron microscope is to focus the electrons and this is done by magnetic fields. Suppose beams of electrons travel from left to right parallel to each other each as shown in the diagram. Draw a possible pattern of magnetic field that can be used to focus these beams (to bring these beams to one point).
(b) The electrons are accelerated by using a power source. Calculate the voltage required to produce electron waves with a wavelength of $0.102 \mathrm{~nm}$.
(c) Use the information in (b) to explain why an electron microscope is used to magnify things that are too small to be seen by a light microscope.

Aaron Miller

Numerade Educator

02:59

Problem 6

With the aid of a diagram, describe the experiment performed to prove the existence of matter waves. In your answer, you should mention the principle of interference and diffraction.

Dr. Satish Ingale

Numerade Educator

02:00

Problem 7

(a) Describe de Broglie's electron-wave model of atoms.
(b) Evaluate why his model was successful. In your answer, you should discuss the inadequacies the model addressed and the improvements the model made.

Jheremiah Simon

Numerade Educator

07:25

Problem 8

(a) Define Pauli's exclusion principle.
(b) Using the sodium and argon atoms as two examples, write down a set of possible quantum numbers for these two atoms; explain the meaning and the significance of the exclusion principle.