Author Question: When calculating the Lorenz number L classically for electrical conductivity, you arrive at an ... (Read 56 times)

jon_i

  • Hero Member
  • *****
  • Posts: 549
When calculating the Lorenz number L classically for electrical conductivity, you arrive at an answer that is proven wrong experimentally. Which of the following statements is NOT true about the quantum mechanical contribution to the value of L?
  a. Quantum mechanics provides that thermal conductivity K is proportional to electrical conductivity over Avogadro's number, /NA.
 
b. Only electrons moving near the Fermi speed will be a factor in the conductivity.
  c.Quantum mechanics predicts a larger Lorenz number than classically calculated.
  d. The quantum Lorenz number depends on a different configuration of the same physical constants that the classical number depends on.

Question 2

Which of the following is NOT a general selection rule for the filling of electron shells?
 
a. For a particular n, the subshells fill in the order s, p, d, f, ...
  b.Shielding affects the ordering of energy levels as described by n and l.
  c. The orbital and spin angular momentum in each shell and subshell are restricted by Hund's rules.
  d. Electrons usually completely fill a subshell before starting another shell.
  e. For the s shell there are 2 electrons, for the p shell 6, for the d shell 10, and for the f shell 16.



fur

  • Sr. Member
  • ****
  • Posts: 309
Answer to Question 1

This statement is not true. The thermal conductivity K is indeed directly proportional to the electrical conductivity, but it is also directly proportional to the temperature T, K
a.

Answer to Question 2

e.
This statement is not true. The f subshells each take 14 electrons. Each l value subshell can take 2(2l + 1) electrons.



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
 

Did you know?

Patients who have been on total parenteral nutrition for more than a few days may need to have foods gradually reintroduced to give the digestive tract time to start working again.

Did you know?

According to the National Institute of Environmental Health Sciences, lung disease is the third leading killer in the United States, responsible for one in seven deaths. It is the leading cause of death among infants under the age of one year.

Did you know?

Normal urine is sterile. It contains fluids, salts, and waste products. It is free of bacteria, viruses, and fungi.

Did you know?

Alcohol acts as a diuretic. Eight ounces of water is needed to metabolize just 1 ounce of alcohol.

Did you know?

Lower drug doses for elderly patients should be used first, with titrations of the dose as tolerated to prevent unwanted drug-related pharmacodynamic effects.

For a complete list of videos, visit our video library