by horse Comment Closed

LARN 061 C16D1

Start the following in class:

1.  Metallic, ionic, and covalent bonding are all strong types of bonding.  The required journal focus questions for today, J61,  are

a. How is it possible for covalent molecular substances to have much lower melting points than typical ionic compounds? [Hint: In your response, distinguish between the bonding between atoms within molecules (interatomic, intramolecular bonding) and the bonding between molecules that holds the molecules together in a solid crystal lattice or in a liquid (intermolecular bonding).]

b. Do a little research and list five examples of covalent molecular substances that have a much lower  melting point than ionically bonded sodium chloride.

2. The study of carbon containing compounds other than those that contain the carbonate ion is called organic chemistry. Go to the web site at http://www.visionlearning.com/reg/login.php, log on into the course+section for which you are registered, and select the module entitled Carbon Chemistry. Read this module as if you were creating an SQ5R or PQ5R study guide for it, but title it: In Class: Carbon Chemistry.  Click here to read  the full instructions for what you need to do.  When you are finished, click on the Questions > Quizzes tab at the top of the module and then click on the Chemical Bonding title, select the best choice response to all the quiz questions and then click on the Score Quiz button.  Then examine the feedback on your quiz and reread and study the material pertaining to any items identified as incorrect.  Reflect on your responses and retake the quiz as many times as you need for you to fully understand and from that understanding, score well on the quiz.

3. Log on to the ChemThink web site http://simbucket.com/chemthinkserver/chemthink/ to do the tutorial and question set on Ionic Bonding.

  • Choose menu selections:  Assignments > Covalent Bonding Tutorial.  [If you are logged onto the ChemThink web site, you do this by clicking on the green triangle in the white circle to the right of the displayed module’s name. If you were taken directly to a web page with an orange Tutorial button and a blue Problem Set button, click on the orange Tutorial button.]
  • If you do not have a copy of the worksheet that goes with this module, click on the provided link to the ChemThink worksheet for this module or, if that doesn’t work, locate it in the Student Resources > Handouts > ChemThink Formative Assessment Note Sheets folder. Download the worksheet, and print off a copy.
  • Place your hand in number and name in ink in the upper right corner of the worksheet.
  • Now work your way through the online tutorial.  You will have to answer each problem correctly to advance to the following page. FYI: When there are check boxes given before possible correct responses in either the tutorial or the problem set, more than one response may be correct, so carefully consider each response before submitting your answers.
  • Record a response to each question asked on the worksheet.
  • Then choose the menu selections:  Assignments > Covalent Bonding Question Set to formatively assess the understanding that you have built up by doing the Tutorial.  Try to do each problem in the Problem Set correctly during your first attempt at working your way through the problem set.  If you get a problem wrong, focus on understanding why each problem in the question set is answered in the way that it is.   Your goal is eventually to have a deep enough understanding to score 10 out of 10. If you did not attain that level of understanding the first time through, review some more, and do the problem set again until you have mastered the content with a 10 out of 10 score.
  • Place the worksheet in the Notes section of your 3 ring binder and bring it to class.

Diagramfix:

If your Chrome browser displays the questions but not the diagrams for a ChemThink assignment, it is because Chrome needs to be updated to a version that supports the webgl 2.0 standard.  Actions you can do to try to get the diagrams displaying:

  1. Clear the Chrome cache:
    1. Hold down CTRL+SHIFT+DELETE
    2. Enter All time
    3. Check all boxes
    4. Click on Delete
    5. Close the Chrome browser
    6. Open the Chrome browser and go to and log on to the ChemThink website
  2. If that doesn’t work:
    1. Enter Chrome://flags in the address bar
    2. Search for webgl
    3. Enable Webgl 2.0 compute
    4. Click Relaunch at the lower right.
    5. Go to and log on to the ChemThink website

Recommended for those who have time left in their 45 minute study period, but not required of all:

1. Take out the worksheet entitled “Property to be understood” distributed during study of ionic and metallic bonding.

  1.  Fill in just the Covalent Molecular Substance column on the worksheet entitled “Property to be understood” using blue or black ink.  Think about the sixteen properties of metals listed.
  2. In your Learning Log explain how the lack of electrical and thermal conductivity of covalent molecular substances is related to the localization of electrons in the atomic kernels and in the one, two, or three pairs of bonding pairs of negative electrons localized between each two positive nuclei or kernels of bonded nonmetal atoms.
  3. In your Learning Log explain how the strength along a chain of bonded nonmetal atoms in a covalent molecular substance is related to a model in which each two positive nuclei or kernels of bonding nonmetal atoms are held together by their attraction for the same one, two, or three bonding pairs of negative electrons located in the region between the positive charges.
  4.  In your Learning Log explain how the lower melting and boiling points and relative softness of a covalent molecular substance is related to the length of the molecular chains and to the weakness of the intermolecular forces of attraction operating between, and holding together, the chains of covalently bonded atoms that make up a substance. 
  5. In your Learning Log record at least one question question you would want to ask your classmate or teacher about the above mentioned properties.