The Science Fair

Our co-op held a little science fair this morning. The boys have been working on their experiments for the past month and finished up their project boards yesterday.

Cohen tested different substances on ice to see which one melted ice the quickest and which prevented ice from forming.


He found that melting salts melted the crystals. Sand and kitty litter didn't melt any ice and that all salts- rock, table and melting- prevented ice from forming.

Here he is with his board, ready to talk about what he did.

Cale tested growing seeds in different types of light: sun, incandescent and a grow light.


He found out that, like he expected, sun produced the healthiest plants. The incandescent bulb produced long stringy stems that eventually snapped and died within 4 weeks.


Here he is with his final project.


Rylan tested different growth mediums and pineapples. He tested sand, soil and water.


His guess was that soil would grow the best but found out that water was the best way to start the roots.


And here's his board. He was nervous about presenting but it only took a few prompts to get him talking.

And Lakin chose to try watering plants with different things. Water, Coffee, Vinegar and Milk. He started with zucchini seeds of which only one sprouted. But surprisingly, this healthy sprout came from the coffee.


We restarted his experiment with grass seed, which just started to sprout...water had the most sprouts followed by coffee and none in the vinegar and mold in the milk.


The kids all took turns talking about their projects.


We had a baby bird, bird nest types and seed preference, Kool-Aid Chromatography, and a solar oven.


They all did such a good job. And mine are even open to the idea of entering the real science fair next year.

Light: Expansion, Translucency and Shadows

Yesterday we did a couple of activities dealing with how light expands as it moves outward.
First we focused our beam of light on a small object so that the light only hit the object. Then slowly moving backwards and watch the light beam grow larger and larger.

Then we split the beam into rays and shadows to observe how only the center ray travels straight ahead, while the others spread out to the sides.

Cale's notebook:


Finally they made designs on tinfoil and placed them on a cup with a flashlight inserted through a hole in the bottom. They played around in the dark seeing how big they could get their designs to expand on the wall.


We finished yesterday by testing and classifying items according to their translucency. They gathered items and decided if they were transparent, translucent or opaque.

Today we talked about shadows. We read the book What Makes a Shadow, played around with making shadow animals with our hands and made silhouettes.

Can you tell who's who?

Chemistry and Lines

Is it Chemical or Physical?


That was the question for our science get together this week. I set up about 5 fairly simple science activities for the kids to work through and determine if a physical or chemical change occurred.

We started simple- adding hot water to solid ice. To produce the physical change of matter.


Then we moved on to adding our "chemical" aka bleach to a tube of colored water and produced a chemical change- proved by the color change.


Then another simple physical change- each pair broke an egg into a jar...and then stirred it. All physical changes- it was still an egg.

On to a simple version of elephant toothpaste. Which was a water bottle with a small amount of hydrogen peroxide in the bottom. Then they added a drop of dishsoap. Then they were each give a cup of 2 T of water and 1/2 a tsp of yeast to mix together...and pour into the bottle.

This one is fun. More exciting than baking soda and vinegar I think. A chemical change as proved by the gas produced (bubbles) and heat.

I wanted to do a bigger version- if I had the higher percentage of hydrogen peroxide....Science Bob has a nice version and this one...was really cool looking....

And our final experiment was making flubber. A very small amount of it. Each kid was given a tube containing about a Tbsp. of premixed water and borax and a cup of about a Tbsp. of glue. Then they mixed the 2 and shook until the reaction took place. The formation of a solid/precipitate proves the chemical change.

We then moved inside for LINES

We talked about types of lines from simple horizontal and diagonal to more complex contour lines. They each sectioned their pages into about 9 squares and drew different types of lines in each section. While they were doing this I showed them various artist's prints to see the usage of lines in each.

Then we moved on to blind contour drawing. They did really good at this. I warned them it might be a frustrating task, but that it was good practice and a way to train your eyes to draw what they see. We started with drawing a bottle and then they began to gather other objects to attempt to draw blindly. Pencils, baskets, their hands and feet....

The final activity was to use contour lines to add depth and detail to their drawings. We started by tracing hands on to the paper and then observing the difference between that and the real thing. Then they began to add all those little lines to their hands- nails, knuckles, creases- to give the hand more detail.

Aliens and Water

We started out by painting backgrounds- the alien planet and surrounding space....

While those were drying we made symmetrical aliens.... by cutting half an alien shape on the fold of a paper. This was frustrating to some and easy for others.

Then we decorated...

Using oil pastels, pom-poms, LOTS of googly eyes and other various craft items


Then the aliens went home to their planets. In our group of 11 we got many different types of aliens- from big blobs to small and intricate.

"Picnik Show"

Create a free slideshow with Picnik!

Then on to water experiments. Where they discussed displacement, buoyancy and density.

At least I think they did...I was busy with the toddlers finding random items throughout the house to float and sink and making puddles on the table.

The bulk of the experiment time was spent using clay and trying to form a boat that would float. Once they perfected their designs, they went in search of passengers. From little dinosaurs to teddy bear counters to Lego men....

See ya!

Chemistry Unit- Lesson 12

Lesson 12:
Acids and Bases


First off we made Turmeric Paper. To do this put 1/4 cup alcohol in a bowl and stir in 1/4 tsp of turmeric. Dip coffee filters in the solution until completely covered and yellow. Hang up or place on a cookie sheet to dry.
Once dry, cut them into strips. Now they can be used to test for bases....and acids.
(recipe taken from Janice VanCleave's Chemistry for Every Kid)

Now on to our experiment....

We had a very simple discussion on what acids and bases were. I mentioned that acids have excess hydrogen and bases have excess hydroxide. But mostly we talked about the properties....in terms they know....stomach acid, acid rain, sour, sharp, etc....

We had several solutions to test:
milk, lemon juice, hydrogen peroxide, water, baking soda, borax, saliva, vinegar, bleach water....

One by one we tested them using our turmeric paper....if they produced no change we knew it was not a base...either acid or neutral. If the strip turned red, the solution was basic.

Once we went through all the solutions one time, we retested those solutions that produced no change, but this time we tested them on the strips that were already red. If the strip stayed red....it was most likely neutral. If it turned back to yellow the solution was an acid.

Here's a sample of a basic solution:

Here's a sample of a acidic solution:

Once we ran through our tubes, they went to the kitchen and picked a couple more: apple juice, alcohol and pedialyte.

The results:

acids: lemon juice, peroxide, vinegar, bleach, apple juice and pedialyte
bases: baking soda (with water), borax (with water) and milk
neutral: tap water, alcohol and saliva
_________________

The End
And that concludes our chemistry unit....our 4 weeks are up and we are moving on to Rocks and Minerals....provided I can get it all planned in the next week. We've had a lot of fun with Chemistry though....so we might throw some random experiments in from time to time....

Chemistry Unit- Lesson 11

Lesson 11:

Determining if a chemical change has occurred by observation of generation of heat.

Supplies:
1 tsp yeast, 1/4 cup hydrogen peroxide, stirring stick, thermometer

Record beginning temp of the peroxide (67 degrees)

Mix yeast into the peroxide and stir

The mixture begins to bubble and fizz....another sign that a chemical reaction is taking place. If you keep your hands on the outside of the bowl you can feel it begin to heat up.

Record ending temperature (90 degrees)

They were actually pretty amazed by this one. I keep listing the ways to tell if a chemical reaction has taken place....they've seen the bubbling, they've seen the gas given off.....I guess they didn't really believe that heat could actually be created by just mixing 2 things.

Chemistry Unit- Lesson 10

Lesson 10:

Chemical Changes

Objective: To see a color change as evidence of a chemical change
To see fizzing/bubbling as evidence of a chemical change


Supplies:
3 tubes, labeled #1-3
bleach
vinegar
hydrogen peroxide
3 tubes half full with water
food coloring

Procedure:
Place the bleach, peroxide, and vinegar in each of the tubes labeled #1-#3.
Drop one drop of food coloring in each of the water-filled tubes.

Place one dropper full of solution #1 into one water-filled tube. Observe. Continue for each of the 3 solutions.

The bleach will produce an immediate color change. The vinegar will produce none.

Over the next few minutes the tube with bleach added will become more and more colorless. I added the peroxide on this one. I thought it would produce some sort of change, considering it is used to bleach some things....but no change occurred. Even after adding more than one dropper full.

Experiment 2:

We've done this one before. But it was a hit then, and this time we talked a little more about the why behind it and what was taking place.

Step 1: Fill up a bottle/tube about half way with vinegar
Step 2: Funnel a couple of tablespoons of baking soda into a balloon.

Step 3: carefully stretch the neck of the balloon over the bottle. Be sure not to allow the baking soda to fall into the bottle yet.
Step 4: Lift the balloon to allow the baking soda to fall into the bottle and mix with the vinegar. You may want to hold on to the neck of the bottle/balloon just in case.
Step 5: Watch! The balloon will inflate as the reaction between the vinegar and baking soda produces carbon dioxide.

Chemistry Unit- Lesson 9

Lesson 9:
Physical or Chemical?
6 trays set up as follows:

tray 1: a bowl with an ice cube
tray 2: a tube containing vinegar and one containing baking soda.
tray 3: an apple, plate and a knife
tray 4: a tube containing vinegar and a bowl containing steel wool
tray 5: a plastic back containing a rock and a hammer

tray 6: a candle and a lighter

Their job was to determine whether a chemical change, physical change or both took place.

Phyiscal:
the ice- changes in state of matter
the rock- change in shape
the apple- change in shape

Chemical:

the apple- color change caused by oxidation
the steel wool- rust formation caused by oxidation
the baking soda and vinegar- bubbling, gas formation

the candle- gas formation, odor

We watched the candle (small, birthday cake candle) until it was completely gone. This showed even more than the previous experiment....the wax was almost completely vaporized, where as the previous one had a substantial pile of wax left once it was burned out. While it burned we talked about the parts of the flame. Where it is the hottest, coolest and what is going on in each part. We also talked about open flame safety rules.

I am also fairly certain I could give them a box of baking soda and a bottle of vinegar and they'd be entertained for a very long time.