« previous next »

Author Question: In drawing the Lewis structure for the dichromate ion, how many valence electrons does chromium have? (Read 1186 times)

sammy

  • Hero Member
  • *****
  • Posts: 818
on: Sep 20, 2013
The periodic table says that Cr has only 1 valence electron but other sources say that when drawing a Lewis structure, it is considered to have 6 valence electrons. Why?


erika

  • Hero Member
  • *****
  • Posts: 522
Reply #1 on: Sep 20, 2013
6 is correct. Cr2O7(-2) gives you 7 oxygens = -14 + (-2) = 12 divided by two Cr per anion = 6 for the formal valence of Cr in dichromate.


Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question

theo

  • Hero Member
  • *****
  • Posts: 698
Reply #2 on: Sep 20, 2013
The six valence electrons of chromium are the 4s2 and the 3d4. In this way, the chemistry of chromium is analogous to that of sulfur, 3s2 3p4.


sammy

  • Hero Member
  • *****
  • Posts: 818
Reply #3 on: Sep 27, 2013
Marking this topic solved :D

Thanks so much for the help


« previous next »
 

Did you know?

Street names for barbiturates include reds, red devils, yellow jackets, blue heavens, Christmas trees, and rainbows. They are commonly referred to as downers.

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?

The Centers for Disease Control and Prevention has released reports detailing the deaths of infants (younger than 1 year of age) who died after being given cold and cough medications. This underscores the importance of educating parents that children younger than 2 years of age should never be given over-the-counter cold and cough medications without consulting their physicians.

Did you know?

A cataract is a clouding of the eyes' natural lens. As we age, some clouding of the lens may occur. The first sign of a cataract is usually blurry vision. Although glasses and other visual aids may at first help a person with cataracts, surgery may become inevitable. Cataract surgery is very successful in restoring vision, and it is the most frequently performed surgery in the United States.

Did you know?

Anesthesia awareness is a potentially disturbing adverse effect wherein patients who have been paralyzed with muscle relaxants may awaken. They may be aware of their surroundings but unable to communicate or move. Neurologic monitoring equipment that helps to more closely check the patient's anesthesia stages is now available to avoid the occurrence of anesthesia awareness.

Types of changes in chromosome structure Types of changes in chromosome structure
Cell-wall structure of Gram-positive and Gram-negative bacteria. Cell-wall structure of Gram-positive and Gram-negative bacteria.
Retrovirus Structure Retrovirus Structure
Exon–intron structure of the ovalbumin gene in chickens Exon–intron structure of the ovalbumin gene in chickens
The tertiary level of protein structure for the respiratory pigment myoglobin The tertiary level of protein structure for the respiratory pigment myoglobin
Structure of roots Structure of roots
Video: Phases of the Female Reproductive Cycle - Hormonal regulation

For a complete list of videos, visit our video library