5. Prepare a table that lists the colors associated with the metal cations.

The photoelectric effect is used today to make light-sensitive detectors; when light hits a sample of metal in a sealed compartment, a current of electrons may flow if the light has the proper wavelength. Cesium is a desirable component for such detectors. Why?

Chapter 3 introduced the concept of a double bond between carbon atoms, represented by C=C , with a length near 1.34 Å. The motion of an electron in such a bond can be treated crudely as motion in a one-dimensional box. Calculate the energy of an electron in each of its three lowest allowed states if it is confined to move in a one-dimensional box of length 1.34 Å. Calculate the wavelength of light necessary to excite the electron from its ground state to the first excited state.

Ultrasonic waves have frequencies too high to be detected by the human ear, but they can be produced and detected by vibrating crystals. Calculate the wavelength of an ultrasonic wave of frequency 5.0104s1 that is propagating through a sample of water at a speed of 1.5103ms1 . Explain why ultrasound can be used to probe the size and position of the fetus inside the mother’s abdomen. Could audible sound with a frequency of 8000s1 be used for this purpose?

In the Stern-Gerlach experiment, silver atoms were used. This was a good choice, as it turned out. Using the electron configuration of silver atoms, explain why silver was a good candidate for being able to observe the intrinsic angular momentum of the electron. Hint: Dont use the aufbau principle to determine the electron configuration of Ag, because its one of the exceptions. Look up the exact electron configuration in a table.

Quantum mechanics predicts that the energy of the ground state of the H atom is 13.6eV . Insight into the magnitude of this quantity is gained by considering several methods by which it can be measured. (a) Calculate the longest wavelength of light that will ionize H atoms in their ground state. (b) Assume the atom is ionized by collision with an electron that transfers all its kinetic energy to the atom in the ionization process. Calculate the speed of the electron before the collision. Express your answer in meters per second (ms1) and miles per hour (milesh1) . (c) Calculate the temperature required to ionize a H atom in its ground state by thermal excitation. (Hint: Recall the criterion for thermal excitation of an oscillator in Planck’s theory of blackbody radiation is that hvkBT .)

The speed of sound in dry air at 20°C is 343.5ms1 , and the frequency of the sound from the middle C note on a piano is 261.6s1 (according to the American standard pitch scale). Calculate the wavelength of this sound and the time it will take to travel 30.0 m across a concert hall.

What is the energy of light having each characteristic? a v=6.031014s1 b =9.27nm c v=4320cm1 d =5.69

6.10 Define the term refraction.

Light of very long wavelength strikes a photosensitive metallic surface and no electrons are ejected. Explain why increasing the intensity of this light on the metal still will not cause the photoelectric effect.