Modern Physics, 3rd Edition
3rd Edition
ISBN: 9780534493394
Author: Raymond A. Serway, Clement J. Moses, Curt A. Moyer
Publisher: Cengage Learning
expand_more
expand_more
format_list_bulleted
Question
Chapter 7, Problem 18P
To determine
Verify the claim that the electrons of a metal collide with the surface at a rate of about
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solutionStudents have asked these similar questions
Germanium doped with 1024 m Al atoms is a semi-conductor at room temperature and
each Al atom creates a charge carrier.
Calculate the electrical conductivity of this material at room temperature, considering
that the electron and hole mobilities are respectively 0.1 and 0.05 m/V.s.
In solid KCI the smallest distance between the centers of a. potassium ion and a chloride ion is 314 pm. Calculate the length of the edge of the unit cell and the density of KCI, assuming it has the same structure as sodium chloride.
7.7 The measured thermal conductivity of germanium at 300°K is
0.63 W/°K, in a range where acoustic phonon scattering dominates.
(a) What fraction of this thermal conductivity is caused by free electrons
if the free-electron density is 1017 cm-³ and the electron mobility is 4x 10
cm2/V-sec?
(b) What must the concentration of free electrons in germanium at 300°K
be in order for the electronic contribution to the thermal conductivity to be
equal to the lattice contribution?
(c) The thermoelectric power corresponding to (a) is measured to be
0.46 mV/°K. How far below the conduction-band edge does the Fermi
level lie?
Chapter 7 Solutions
Modern Physics, 3rd Edition
Knowledge Booster
Similar questions
- = 1.663. (a) Show that the c/a ratio for an ideal hexagonal close pack (HPC) structure is (a) Sodium transforms from BCC (lattice constant = 4.23Å) to HCP at about T = 23K. Assuming that the density remains fixed, and the c/a ratio of the HCP stacking is ideal, calculate the lattice parameters (i.e., a and c) of the HCP lattice. J M K Ja N d M K A K c/2arrow_forwardThe conductivity of a metal is 5.6 x 105 Ohm-¹cm¹ and the density is 8.92 g/cm³ with an atomic mass 62.5 g/mol. Determine the following: i) drift mobility and ii) mean time between the scatterings.arrow_forwardAt room temperature, pure germanium has an almost completely filled valence band separated by a 0.67 eV gap from an almost completely empty conduction band. It is a poor electrical conductor, but its conductivity increases greatly when it is irradiated with electromagnetic waves of a certain maximum wavelength. What is that wavelength?arrow_forward
- Aluminum has a density of 2.70 x 103 kg/m3 at a temperature of 293 K, and its molar mass is 26.98 g. (a) Compute the number of aluminum atoms per unit volume at that temperature. (b) Use the fact that EF 11.63 eV for aluminum at 293 K to fi nd the number density of free electrons. (c) Combine your results from (a) and (b) to estimate the number of conduction electrons per atom—the valence number for aluminumarrow_forwardEstimate kBT at room temperature, and convert this energy into electronvolts (eV). Using this result, answer the following: (a) Would you expect hydrogen atoms to be ionized at room temperature? (The binding energy of an electron in a hydrogen atom is 13.6 eV.) (b) Would you expect the rotational energy levels of diatomic molecules to be excited at room temperature? (It costs about 10−4 eV to promote such a system to an excited rotational energy level.)arrow_forwardA Si p- n junction with cross sectional area A= 0.01cm? is formed with N3=2x1017 cm3, Na= 1017cm3. Calculate: a) contact potential b) the depletion region width and c) the junction capacity at 0 and -2 Volts.arrow_forward
- The maximum wavelength of light that a certain silicon photocell can detect is 1.11 mm. (a) What is the energy gap (in electron volts) between the valence and conduction bands for this photocell? (b) Explain why pure silicon is opaque.arrow_forwardIn this and following questions, we develop a model for spontaneous emission of a photon by a diatomic molecule AB (a model molecule), which rotates and vibrates. In intermediate calculations, atomic units (a.u.) will be used: unit of mass = the mass of electron, unit of charge is the proton charge e, (e is a positive constant so that the charge of electron is -e). The initial state of the molecule is an excited rotational (1=1) and excited vibrational state (v=1). We consider a molecule with the reduced mass µ = 10,000 a.u. (it is similar to the mass of CO). After emitting a photon, the molecule will go to the 1=0, v=0 state. The first question is about the model potential of the molecule. It is represented by a potential of the form: V(r) = C6 p12 C12 p6 " where r is the distance between A and B in the molecule, C6 and C12 are positive constants (C6 =2 and C₁2-1). This potential has a well meaning that the molecule is bound. The first thing to do is find vibrational states of the…arrow_forwardAu is face-centered cubic metal with lattice constant 4.08 Å. If the atomic mass of Au is approximately 197 calculate the number of conduction electrons per unit volume (electrons/cm) and number of electrons per unit mass (electrons/g). Assume that each Au atom donates one conduction electron.arrow_forward
- The potential energy of a system of two atoms is given by the relation U =-A/r + B/r10 A stable molecule is formed with the release of 8 eV energy when the interatomic distance is 2.8 Å. Find A and B and the force needed to dissociate this molecule into atoms and the interatomic distance at which the dissociation occurs.arrow_forward(a) What is the minimum donor doping required to convert silicon into a conductor based on the definitions in Table ? (b) What is the minimum acceptor doping required to convert silicon into a conductor?arrow_forward(a) Describe the free electron gas model of metals. How does it help to explain the lattice heat capacity and electrical conductivity of metals?arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
- Modern PhysicsPhysicsISBN:9781111794378Author:Raymond A. Serway, Clement J. Moses, Curt A. MoyerPublisher:Cengage Learning
Modern Physics
Physics
ISBN:9781111794378
Author:Raymond A. Serway, Clement J. Moses, Curt A. Moyer
Publisher:Cengage Learning