Molecular liquids (water, gasoline .....) and molecular solids (sugar, wax.......) are actually individual particles that are attracted to each other, yet not necessarily connected to each other.
Standard 1- Basic operation and concepts
Standard 3- Technology productivity tools
Standard 5- Technology research tools
Applications- Used to micro engineer molecules
Information Literacy -
Standard 1- students will access information efficiently and effectively.
Standard 2- students will evaluate information critically and competently
Standard 3- students will use information accurately and creatively.
Reside at the heart of the discipline
Interactions of matter
Represents a big idea having enduring value beyond the classroom:
Why some items are miscible and others aren't.
Require uncoverage, meaning that misconceptions need to be identified and clarified:
IMF's are not actual bonds.
The weaker IMF(s) are working even while the predominate IMF is working.
Offer potential for engaging students:
Surface Tension activity - relates why water can round up on a coin while alcohols don't.
Fuller Than Full - Explains why you can fill a glass of water fuller than full.
-While working on assignments and during class discussions the teacher should look for clues that suggest student misconceptions. This may be accomplished by using `Pictures in the Mind', exit cards or written prompts.
-There will be a quiz on which the student correctly identifies the predominate IMF acting on a chemical species, and ranks relative IMF strengths.
-Informal checks will be used to assure that the student can describe how a particular IMF influences the process of any phase change for a chemical species. These may include exit cards or sketch drawings.
-The students must present an explanation of how an IMF acts on a particular chemical species. (Options for explanation could include short answer, explanation of specific laboratory results or class presentation)
a. Identification of IMFs
Students will participate in an activity that shows objects of various sizes and shapes. This activity is to help students that the physical structure of the molecules will have an effect on its ability to "hold" onto other molecules (IMF). Some items with `handles' are easier to grasp thus would have a higher intermolecular force of attraction to other molecules. This is followed with information / discussion of how molecules hold together using IMF's to form solids and liquids.
b. The teacher and students will look at the polarity (molecular geometry) and electronegativities of the elements in a compound and will determine what type of IMF is predominate. After some practice students will attempt this for themselves. Prediction of lab data will follow. Students will perform the IMF-Evaporation lab. Students will use a CBL to measure Rate of Vaporization (Inverse of the IMF) and a graphing application to accumulate and present data. The data is completely gathered and transferred electronicly.
c. After the IMF-Evaporation lab students will write an appropriate conclusion that explains how each type of IMF affected the change of phase (evaporation) of the chemical species involved and relate the energy changes involved. Students will practice and discuss IMF ranking with other sets of chemical species.
d. On a final evaluation (quiz?) the students will relate lab information, rank IMF strengths, rank chemical species and explain the ranking with respect to a particular physical property (melting point, boiling point.....)
Information Manager / Effective Communicator / Creative and Critical Thinkers / Ethical and Responsible Workers / Systems Manager / Cooperative Workers