After School Science: Polymers

What words do you know that start with Poly-? 

Polygon,  Polyester  (responses I received from eight 3-5 graders) 

Poly-"many" in Greek 

Mer - "parts" in Greek

Polymer- a large Molecule made up of long chains of repeating units called monomers.

Water Storing Crystals are the polymer, polyacrylamide.  This chemical polymer was first used to absorb water in places where a pump could not be used.  It is also used in agriculture to keep soil moist. 

These creepy crawlers or Gro-beasts are also made of polyacrylamide.  It is also found in super absorbent diapers.

The package of "creepy crawlers" comes with a spider, a scorpion, a cockroach and a centipede.  You could talk about Arthropods here!

The experiment:  Does your grobeast "grow" 600%?  
We measured the length using a ruler (centimeters ) and we used an electric balance in grams.  

You could discuss why scientists use the metric system (it helps to use the same system of measurements if you are sharing your experiment) and why scientists use mass instead of weight  ( I did have one student in my group tell me it's because of gravity!)

I had the students calculate how big their arthropod would get if it "grew" 600%.  This could be a hard concept, but once one student said the 600% is just 6 times the size of it,  they were able to calculate it.  In the case of the spider, it was 4 cm at start and 
9.4 cm after 3 days in water.  If it had grown to 600% it would have been 24 cm ( the diameter of the plate).  Its mass after 3 days went from 2.1 g to 17.8 g,  which is more than 600% by mass.  

Some students in the class had made "slime" before.  It is an example of a cross-linked polymer made from polyvinyl acetate (found in Elmer's glue) and sodium tetraborate ( borax).  Here is the recipe for slime: 

Prepare Borax Solution: 2 Tablespoons of borax into 2 cups of water, stir until dissolved. ( more than enough for 30 students)

Mark a plastic cup at the 20 ml mark by pouring 20 ml of water from graduated cylinder. ( you do not want to get glue out of a graduated cylinder!) Pour glue to the 20 ml mark and add 20 ml of water.  Stir.  You could add food coloring here. 

Add drop wise the borax solution, stirring until a mass of "slime " is formed. Carefully rinse under running water to get rid of excess borax. 

Students can test the properties of their "slime" for:
Stretch-ability
Bounce-ability 
Ability to make a puddle
Print-ability ( use water soluble markers or newspaper print like silly-putty)

***  Please don't let children take home the "slime" unless it is in a plastic baggie and has a warning label taped to it.  You could decide as a group what should be written on the label. 

Example:  Warning:  Do not eat or throw.  Do not place on furniture.  May cause discoloration on clothes. Not suitable for kids under 4. 

If the students are not going straight home, I take the slime back and make one big ball for observation in the classroom.  This especially goes for high school students who have other classes to go to.  Their teachers will appreciate this rule.  

We also looked at these grow capsules made out of synthetic sponge material.  

I included "Magic Sand" in this class because it is hydrophobic, it is not a polymer. The polyacrylamide is hydrophilic.


The polymer, polystyrene can take many forms.  Many students were familiar with styrofoam.  But polystyrene can be hard plastic like for a computer casing, as well as a clear plastic top at the salad bar.   

 The experiment:  Does # 6 plastic (salad lids) shrink just as much as the "Shrink-it" you can buy in the store? 

The package claims it shrinks 60%.

Obtain a piece of "shrink-it".  Sand the entire piece with a medium to fine sandpaper.   We used colored pencils,  but you could experiment with "sharpies" and crayons too. Trace around your piece and measure its width in centimeters.  Place in a toaster oven on a piece of cardboard or Al foil (that is just used for experiments) at 250 degrees and watch very carefully. (Adults only handling plastic) Remove after transformation (no more than 5 minutes). Measure the "after" and do the math! Estimation could also be used here!  Repeat again using a piece of # 6 plastic from a salad top.
Compare!
Recycling plastic could be discussed here!

We are examples of Natural Polymers! DNA
I also passed around some of my Pygora goat's fiber and sheep's wool as examples too! 

Polymers are everywhere!

After School Science: Rocks and Minerals

 Lesson today on Rocks and Minerals.  

Rocks 

Igneous - formed from fire

Sedimentary - formed in layers

Metamorphic - formed from pressure

Rocks are mixtures and have no definite chemical composition

Rocks are made up of minerals

Minerals

Minerals are pure substances and are made up of elements 

Minerals have chemical formulas, which means they form in definite ratios

Minerals form crystals

You can use the Mohs Hardness scale and a streak test to identify a mineral

Samples to show.

Great to use the Smart Board!

We had 8 different samples for the students to identify.  The students labeled their boxes and picked out their samples.

The finished box with warning label: Keep away from small children.  Do not place rocks and minerals in your mouth!

Honey Tasting

Last weekend I had the opportunity to attend a two day workshop on honey tasting.  The workshop was led by Marina Marchese and Raffaele Dall'Olio.  Both are expert teachers trained in Italy.  I know Marina personally because she is a past president of the BYBA ( the bee club I belong to).

Marina's book The Honey Connoisseur is a fascinating read.  It's full of information on the sensory analysis of honeys from all over the world. 

Why take the Workshop?  Because where else can you sample 20 different  honeys and learn how to use your senses to tell them apart!  Not all honeys are sweet!

The darkest honey in the photo is Buckwheat.  It also has a strong taste.  

This is Sunflower Honey from Italy.  Its color was bright golden yellow and it had a fruity flavor, but was not very sweet.   It had a pineapple aroma . 

This is a sample of Goldenrod Honey.  The flavor was intense, spicy and warm.  It tasted sweet and floral and had a floral aroma. 

This is a sample of Citrus Honey from Florida.  Its color was extra white.  This honey tasted like its aroma, like a fresh, floral citrus flower.

Pairing cheeses with honey.   I really enjoyed this part of the workshop!

It also was fun to talk with everyone about our lives with bees!

Math Night

Origami Night! Oh! I mean Math is Fun Night! 

Japanese
 Ori -folded  gami- paper

 Vocabulary 

Add:   Right Triangle

I had many origami books on hand.














Examples: 

 Bouquet of origami irises

It It was good to have parents help with the folding.

 Everyone should know how to fold an origami crane.  It can bring good luck and long life!

Basic steps to make a crane.

Make a crane to go along with the Japanese folktale "The Crane Wife".

Or make a crane to go with a Japanese haiku.

My Favorite Origami Ornament

Every year, a week or two before Christmas, when I'm not making cookies, I like to make origami ornaments for the tree. Some for giving, some very tiny for my feather tree and some just for hanging around the house. 

I collect origami books.  These 3 books were the first books I "read".  I didn't have to know how to read to enjoy them.  I just followed the diagrams and made something to play with!

 Tree for tiny origami.


I am going to attempt to write directions for my modular origami ball.  (This is really for me, because I keep taking a ball apart every year, because I forget how to do it!)

Pick 12 square pieces of paper.  It can be wrapping paper, pages from a magazine, and of course origami paper.  Its fun and good for the environment if you make it out of paper that has been recycled. 
(These are 4 inch squares.)

Fold in half and then fold to the center line on each side.

Fold the corner up.

Then the other corner down. 

Tuck each corner inside.  You need to make sure each piece is folded the same way.

Turn each piece over, and fold up the ends to make flaps.

The first three pieces fitted together. The flaps fit into pockets on another piece. 

Six pieces together.

one piece left. 

Finished!

Making Quince Jelly

There are two quince trees (they look more like bushes) near the house and garage at Blue Button Farm.  I don't know how old they are, but if I had to guess, maybe they were planted in the early 1950's. Quince trees were common in colonial America. There was at least one in every orchard in New England ( they are self-pollinating) and they are in the same family as the apple, pear and rose. Quince fruit was not a favorite because raw, they are hard and sour, but when baked, the white flesh turns red, soft and sweet.  Quinces naturally contain a large amount of pectin, which makes them perfect for making jelly.  

The quince tree in the Spring.  The flowers have a wonderful fragrance. This fruit bearing quince should not be confused with the ornamental Japanese flowering quince.

When ripe, the fruit turn a golden yellow and give off a floral fragrance. This usually happens in October around here.  This Quince tree needs to be pruned. Even with years of neglect, it still produces fruit.

First step in making Quince Jelly is to collect only ripe fruit.  They should be yellow and the blossom end should smell fragrant.

Chop the fruit up and discard the cores.  Don't bother trying to peel the fruit. Add enough water to cover plus an inch. Bring to a boil, cover and simmer until the fruit is soft ( about an hour).

Using a potato masher, mash the quince to the consistency of slightly runny applesauce. (Notice the change in color of the fruit.)

I strained the juice from the pulp by pouring it through two layers of cheese cloth draped over a strainer. This may take a couple of hours .





I had about 4 lbs. of chopped quince and it made 10 cups of liquid.  Bring the liquid to a boil and add 8 cups of sugar.  Stir constantly until the sugar is dissolved.  Hang a candy thermometer on the side to monitor the jelly temperature.

As the jelly cooks, skim off the foam that comes to the surface and sterilize your jelly jars and lids. 

The jelly stage can occur between temperatures 218 and 220 degrees.

To test for the jelly stage, pour a teaspoon of the jelly on a chilled plate. If it feels firm and "wrinkles" it is done and ready to be poured into hot jars.