Miss Gail is planning an experiment with diapers like this one…

Keywords for kids:

Water molecules.  You have to start somewhere, right?

Polymer.  A polymer is a long ‘snakey’ molecule made of a chain of little molecules linked together.  The little molecules are called monomers.  Get it? ‘Mono’-mers and ‘Poly’-mers… Sometimes scientists like to call things ‘multimeric’ if they have more than one part, as in ‘Multi’-mer…

Hydrogel.  A Hydrogel is a special kind of polymer that really likes to ‘play’ with water molecules.  This one is called polyacrylate.  There are similar hydrogel polymers that are in contact lenses.

The way hydrogels stick to water is similar to how water sticks to itself… each of the little molecules (the ‘monomers’) that the polymer is made of has a part that is really good at sticking to water molecules. Since all the monomers are linked together in a chain, it is like linking all the water molecules together in the chain as well.

Here is a little experiment, and I don’t know the answer:

Polyacrylate can hold 200-300 times its weight in water.  After that it will either dissolve or it just won’t soak up any more water.  If the polyacrylate polymers are ‘crosslinked’, they won’t dissolve.  If there are no crosslinks, they will dissolve (or they should dissolve, LOL).  ‘Crosslinking’ means that in addition to the long polymer chains, there are some extra molecules that have somehow been mixed in that link the chains together.  Can your kids figure this one out?  How do they know if the polyacrylate polymer won’t hold any more water?  How do they decide if it has dissolved?  Can they compare it to something that does dissolve, like sugar or salt?  If the polyacrylate doesn’t dissolve right away, it may need to sit out for a few days or be heated up to be really sure it won’t dissolve.

Now that the kids have gotten their hands ‘dirty’, we’re ready to move on.

The main ‘trick’ soap can do is to break up, or ‘solubilize’ oil in water.  The chemistry keywords in this lesson are ‘solution’, ‘soluble’, ‘dissolve’ and ‘solubilize’.

Ultimately, the goal is to get kids to look at how soap can break up oil in water, but this is also an opportunity, if there is time, to let kids explore how water can dissolve some substances, but not others.  Just for clarity for teachers, to make sure the vocabulary is fresh in the mind, when sugar or salt is added to water, it will dissolve, and the water is called the solvent.  The salt, sugar or whatever else is dissolved in the water is called the solute.  Something like sand, which doesn’t dissolve, is described as ‘insoluble’.  Liquids like glycerol which can mix with water are called miscible, and liquids which don’t mix are called immiscible.

This solvent/solute business sounds high-falutin’ but it will come in handy when talking about liquids in many situations, like cooking or, for instance, mixing paints.

As far as specific experiments, here is a nicely documented protocol for an soap + oil and water experiment.

Ever watch a kid wash hands?  What a mess.  Soap is definitely the first molecule kids should learn about.

A fancy name for soap is ‘surface active agent’ or ‘surfactant’.  ‘Surface active’ means it acts upon, or changes, the surface tension of liquids.

Here’s a good activity to start with: water on a penny… try adding soap and see what happens

Here is a kid-friendly video showing how to float a needle and showing how soap lowers surface tension

Here is a pretty cool experiment with milk

These are all examples of how soap is ‘surface active’ or a ‘surfactant’.  The word ‘sufactant’ comes up in lots of random places, so why not teach it to the kids?

Next come the molecules.

Here is a cheesy, but simple-enough-for-kids video showing soap molecules.

The take-home points for kids and teachers alike are that soap molecules have two parts, a long chain of nothing but carbon and hydrogen atoms, and a ‘head group’ that contains what are described as ‘polar’ groups of atoms.  The polar groups interact strongly with water.  The fancy name for this is they are ‘hydrophilic’ or ‘water loving’.  The chain of carbon and hydrogen atoms interacts strongly with oils and grease.  The fancy name for this is they are ‘lipophilic’ or ‘lipid loving’.  A lipid, if you haven’t guessed, is something oily.

This concept, that groups of atoms can be described as ‘hydrophilic’ or ‘lipophilic’ will take kids and teachers a long way in describing chemicals.

A quick, sidenote: the word hydrophobic is used more often than lipophilic, but I think for kids it makes more sense to teach them the word ‘lipophilic’.  This is because ‘hydrophobic’ which means ‘water hating’ doesn’t say anything positive about what the chemical groups do ‘like’.  Also, hydrophobic and hydrophilic sound so similar that I think kids (and possibly teachers) will get them confused.

After learning what the word ‘surfactant’ means, kids will be ready to do some experiments with oil, water and soap, so those will be next.

Teaching kids about molecules is tough if you find yourself sorting through old memories of long ago science classes, grasping for bits of useful information.

Wikipedia is great, but for young learners (and their teachers) we want to slow it down a bit.

This vocabulary list will help provide a map of where we want to go.  ‘Atoms and molecules’ offer new ways of talking about everyday things, and without vocabulary, there is no way to develop ideas.  I’ll link to Wikipedia here, but I hope to develop my own pages with just enough for teachers…

Parts of an atom:

• Protons
• Neutrons
• Electrons

Forms of matter

• Solid
• Liquid
• Gas
• Plasma (the Sun; the inside of fluorescent light bulbs when they are on; some TVs)

Kinds of molecules, by size and shape

• ‘Simple’ molecules (water, air, vitamins, pigments, dyes, drugs)
• Single-chain polymers (protein, DNA, plastic)
• ‘Networks’ of polymers i.e. crosslinked polymers (some plastics, ‘resins’ (like epoxy glue) bug shells/exoskeletons)
• Metals
• Rocks and ceramics

Kinds of mixtures

• Air (mixture of nitrogen, oxygen, water and carbon dioxide)
• solute/solvent (sugar in water–suger is the solute, water is the solvent; tea)
• emulsion (milk, almost any processed food)
• suspension (like an emulsion but it doesn’t last; paints, any mixture of things that aren’t soluble that eventually separate)
• alloys (mixtures of metals)
• copolymers
• cocrystals
• lots of others!

Kinds of molecules by source:

• Organic chemicals (from animals and from fossilized plants underground (coal and oil))
• Inorganic chemicals (from rocks and minerals, water or air)

Kinds of molecules by how they mix with water

• Lipophilic (don’t mix with water–oil)
• Hydrophilic (do mix with water–sugar)
• Amphiphilic (mix with both–soap; lots of drugs, proteins)
• Insoluble (don’t mix with a liquid)

That is a great start… a kindergartener who learns these words will be able to learn more when the opportunity arises.

Bonus: ways molecules interact (‘play’) with each other:

• Bumping (tumbling, shaking and bumping i.e. kinetic energy)
• Zapping (photons/’radiation’/electromagnetic waves i.e. electromagnetic radiation)

This is the week Miss Gail proves that flowers can drink.

Miss Gail here…

This week we did an experiment to prove that plants realy drink water. You will need white flowers on stems.  I use mums or daisies… Take 4 small paper cups with plain water to show the children. Then add food coloring-red, blue,green, yellow and make sure you add enough coloring.  Place the white flower stems into the water and within one hour check with the children what has happened. The flowers should start to show color around the edges.  By the end of the day they should have good coloring on the petals. If you want more color cut the stems on an angle again so the flowers will start to drink again.  As with any good science experiment you should use a control.  Take another stem of white flowers and put it into a cup of plain water.  Of course nothing will happen, but you have proven to the children by the first experiment that plants really drink water. You will love the excitement of your class as they see the flowers changing before their eyes.

Dr. Tad here…

Well, the new school year is under way and we’re already well behind on this blog.  We’ll try to make time up by posting summaries week-by-week, so here is week one…  This is going to be edited as we go.

Week one has many activities as students and teacher are getting to know each other.  Here are a few of Miss Gail’s favorites:

The first is a biology lesson that kids will find helpful for some time to come: We live in a multicultural community and each year kids of all the major ethnic groups are represented in Miss Gail’s class.  Of course, kids wonder about and want to talk about the differences they see.  Miss Gail finds some marigolds or zinnias, or any other flower she can find in multiple colors, shapes and sizes, shows them to the children . Lets use the zinias as an example. Some are the giant varity, some the dwarf, some double blooms, some single bloom, all have many colors.  As the kids are allowed to touch, smell and examine the flowers, Miss Gail  asks are these the same type of flower or different kinds. The children will always guess they are different because of the sizes, shapes, and colors. Then Miss Gail tells them they are the same variety of flower. We then use marigolds and go through the same questions again.  Then she compares people  and  all of the children who are in our class, we have different color hair, eyes, height, weight, color of skin,but we are all people with face, hair, two arms, two eyes, etc. There is no difference in us even if we look different, we are people. Miss Gail does this lesson at the beginning of the year so all different ethnicities will accept each other as friends and equals-just like flowers.

Miss Gail

In September one of the first science lessons I begin with is air. I use the air lessons first because it will be very important for the children to understand when I go to the next science of how seeds travel  I start with explaining how we breathe and how important air is.  We talk about getting the oxygen we need from air . We then talk about how we can prove that we breath in air and blow out  another air.I do this experiment outside because it is wet and messy.  I start our experiment with a cup of water and a straw  for each child and ask them to blow into the water and ask what happens. Next I put some dish soap into the cup with water and the fun begins. The kids love the bubbles .  Be prepared they will want to keep going so bring out lots of water and soap.  With luck there will be some wind and some bubbles will fly into the air.  This will give you another chance to talk about how air travels This year I tried something different and we made out own gigantic bubbles by making our own blow pipes out of oaktag. Take oaktag and roll it into a a not too large pointed tube at top. Put water, dish soap, and a little glycerin, put your new bubble pipe and blow.  The bubble will be gigantic and so will the excitement. When you go back to the classroom discuss what happened and how air was needed both to blow the bubbles, to fill the bubbles, and to have them fly into the air. I will follow these experiments with other air proving projects such as cutting out paper winged “helicopters” and air planes.  Before I take them outside I have the children throw them and or drop them from a high point. Then I take a hair dryer and use the blowing air to fly our creations much higher.  I will also do balloon experiments. I blow up a balloon  and ask the kids why aren’t they standing up like the ones you buy at the stores. Some of the answers where “you need a string tied to the balloon.” We tied a string to the balloon and it did nothing.  I asked for someother reasons from the class. I always try to get their minds working on the problems. Finally I explained about different gases-that the air we breathe is oxygen and we blow out carbon dioxide. The balloon needs a gas called hellium that will allow the balloon to rise. Then we discuss hellium.

Miss Gail here

After I have concluded our experiments with air I go on to how seeds travel.  They already know that air moves objects so we go for a walk to see if we can find any seeds that move by air. Dandelions are always good parachutes and it is so much fun to blow them into the air.  We look for other plants and trees that have seeds that travel by air.  Then I bring in osage oranges I find on the road to show how they roll and we look for and collect walnut seeds and other nuts that roll. We then go onto seeds that animals carry and plant such as burdock. I also explain how animals plant seeds by dropping the ones they want to eat and how pooping animals can plant seeds. This always makes them giggle and never forget.  The kindergarteners love any bathroom talk even if it teaches something.  Bringing in the seeds and looking for them with walks is very important. Hands on experiences, feeling and looking for and touching imprints onto the brain more than just reading from a book and makes it more fun for the kids.  We will then write a science paper on what we have learned.  I discuss what facts they have learned by asking  “What do you remember about how seeds travel? Then I ask them to draw a picture about one fact they feel is important. My aid and I go to each child and ask for the one fact.  We write it on a paper, and give it to them to copy on thier paper. This is one way I teach beginning reading. The child learns how to write a sentence in sequence, space words, and that all the letters of the words have to be kept together, now one letter on one line and another 3 lines away. They also learn to retain facts, and how to communicate them. The high point of my fall seed project is to have the kids and parents and who ever I can get to help to collect whatever dried weeds they can find. Iris, lilly, and wild flowers, cone flower, hydranger, are some dried types we use. Take a plastic cup and put a slice of flower foam for arrangements. The kids pick what weeds they want into the cup in the position they want. I then pour plaster of paris into the cup for stability.  When dried I spray paint the arraingement with gold paint.  As you can see by the picture it is quite lovely and the parents keep it forever and can’t believe the kids did it.  The cups will fit into a vase and look good enough to put onto a table for display.

 children creating weed flower arrangement putting weeds into foam in cup

-Dr. Tad & Miss Gail