Building Polymers ActivityPolymer NotesAnswer Focus Question #2Collect Homework and notebooks

Topic: Solids: Crystalline and Polymer

Focus Questions:#1) What is a crystalline structure

and what does it look like?#2) What are some examples of

polymer and what does their molecular structure look like?

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What do you notice about these pictures?

A solid with a crystalline structure has an orderly, repeating pattern of molecules and atoms

What patterns could we form with these shapes?

Here are pictures of molecules of a crystalline solid in 2-D

90% of all solids have a crystalline structure.

Some examples of crystalline solids include rocks, metal, sand, and salt. What would salt look like if we took a closer look?

Salt is a crystalline solid made of two elements, Sodium (Na) and Chloride (Cl). If you were to zoom into a cube of salt, you would see this.

You and your partner will now create the crystalline structure of salt. Using markers, pens, or highlighters, label half of your marshmallows as (CL) and the other half as (NA). With your marshmallows and toothpicks, create a 3-dimensional structure of salt such as the picture shown below. You will be graded on the accuracy of your structure!

Answer these questions in your notebook after you’re finished.

1) How many Na atoms were in your cube?

2) How many Cl atoms were in your cube?

3) What does crystalline mean?

Summarize what you just read in 3 sentences in your interactive notebook

Mr. Lee will select one student to answer focus question #1

Not all solids are crystalline. Some solids have a polymer structure. Plastic is such a solid and is found in skateboard wheels, tupperware, safety goggles, and on the surface of non-stick pans. What does this structure look like?

“Polymer” is made of two latin roots, “poly” which means “many”, and “mer”, which means “parts”. A polymer is a long chain of repeating molecules that make up a substance.

Some examples of polymers are glass, rubber, plastic, and wax.

You already are familiar with one polymer. Can you guess what it is?

Mr. Lee will draw a comic strip of a polymer being created. Follow along in your notebook.

Activity

You will now build a polymer to see what its structure looks like. We will build the polymer polyethelyne, which we drew in our comic. Watch Mr. Lee build his model first.

Notes

Polymers have a structure that is much more flexible (bends easily) than crystalline structure.

Polymers also have a low melting point compared to crystalline solids. This makes them useful because you can change their shape when they're liquids and let them cool back into solids.

Polymers are called “amorphous” solids. Amorphous means “not having a definite shape.” They're called this because they don't have an orderly pattern like crystalline solids.

Polymers

Polyethelyene molecules are the polymers in plastics. They can be

melted, formed into different shapes, then cooled again to form solids.

Another example: glass blowing

http://www.youtube.com/watch?v=88XxsdXSXAg