Monday, July 23, 2012

Greetings from VT

Ahhh, it was so nice to get away! We have been going through a stressful couple of years, so it was especially lovely that our family helped us get away for a bit to my inlaws cabin in VT. We had our family reunion this past Sat at the Groton National Forest in VT. But for 4 days it was all about the nature and 4 wheeling at the cabin. There was no internet access (much to my horror) or running water, but it was sooo worth it!

Here is my 8 y/o taking his first turn as a solo rider on the 4 wheeler. He had only ridden as a passenger in the past so he was excited. Of course, later in the day, he managed to miss every one of the millions of trees in the yard, but crashed into the corner of the house! lol Both he and the 4 wheeler were fine, we kept it in 2nd geer so they couldn't go too fast.

DJ will be 11 in just a few days. It was his first time as well!

video
DJ's Ride

Xman's Ride
video

Sunday, July 22, 2012

Experiment 12: Erupting Volcano

Experiment 12: Erupting Volcano

I know, most of us have done this a million times, but it is soooo much fun! My kids love erupting volcanos so much that we finally made a permanent volcano so they can erupt it over and over!

Supplies: (most of these measurements are rough)
6 cups flour
2 cups salt
4 tbs cooking oil
2 cups water
Empty soda bottle (16 oz)
Warm water
Red food coloring
6 drops dish detergent
2 tbs baking soda
Vinegar about 1 Tbs
Baking dish
Large bowl

Process:
  1. Stand bottle up in the baking dish
  2. In large bowl, mix flour and salt. 
  3. Add the water (from the 2 cups) at cup at a time. More might be needed. Mix until you result in a smooth & firm mixture.
  4. Use mixture to make the sides of the volcano, smoothing from the neck out and down to the baking dish, trying to make the sides sloping and smooth.Be careful not to cover the opening or drop dough into it!
  5. Let your volcano dry, you could even paint it if you want!
  6. Fill the bottle about 3/4 of the way with warm water.
  7. Add a few drops of red food coloring to the water
  8. Add the few drops of dish detergent.
  9. Add baking soda to water
  10. Slowly add the vinegar and watch the eruption!

What's Happening?
Chemistry (for older kids).
In this experiment you have several chemical reactions that happen in rapid succession. First, the acidic acid in vinegar (the stuff that makes it sour) reacts to the Sodium Bicarbonate in the baking soda, the result is Carbonic acid. But carbonic acid is very unstable, and it rapidly decomposes (an immediate reaction) into carbon dioxide and water. The bubbles in this experiment are from the carbon dioxide. The bubbles flow down the sides of e 'volcano' because carbon dioxide is heavier than oxygen. In this experiment you get even more bubbles because of the dish soap.

Volcanoes:
Why do volcanoes erupt? There are several different types of volcanoes and therefore there are several different types of volcano eruptions. In this experiment we are simulating a Strato-Volcano - this is the type of volcano that has steep sides reaching up toward the sky. The eruption of these volcanos usually occurs in stages. These stages can happen in rapid succession or each stage can last days, months, even years! 

The inside of a volcano is like a bowl with a bunch of straws sticking out of it. Most of the straws go off in different directions. The 'bowl' is the magma chamber. Magma is liquified rock from deep within the earth. There are cracks, or weak spots in e crust that allow the magma to travel closer to the surface. These tunnels (like the straws in the above analogy) are vents. Usually there is one main vent, and many secondary vents.

Did you know it's called Magma when it's underground, but Lava when it's above ground?

The closer the magma gets to the surface, the more ground water is boiled into water vapor. If the vents are open, there might be a constant stream of steam that escapes the vent. This stage usually lasts the longest. Water vapor below ground build pressure. If the vent is open enough, it could release this pressure enough to prevent an eruption from happening for years!

But, if the vent isn't open enough, then the pressure with build and build. This is like shaking a closed soda bottle. Eventually the volcano will blow apart in a violent release of pressure. The first part of this kind of volcanic eruption is made up of rock and super heated gas, the rock and dust is usually what remained of the part of the volcano above the blocked vent. (look at videos of Mt St Helen's erupting, where 1/3 of the volcano was blown away!) this bstage of the eruption is called the Pyroclastic Flow - believe it or not, this type of eruption is more deadly than any other stage. Because it is so explosive, it can happen with little to no warning. And the super heated gases and rocks can be thousands of degrees in temp and travel hundreds of miles an hour! This doesn't give people much time to get out of the way. The next stage of the explosion is the ash cloud. When the volcano violently erupts, the stuff too heavy to fly flows down the side of the volcano in the Pyroclastic flow, but dust and ash is very light, most often it is made up of pumice which is very light, and this ash can be blown miles into the atmosphere, but eventually it will come back to earth. Feet upon feet of ash can fall for days, eve, weeks, after the initial eruption.

If this initial explosion destroys enough of the volcano the magma can leak out. In the final stage of an eruption. This stage isn't very often. Most often the pressure is released in the early stages. But if the magma chamber is high enough, or if enough of the vent is blown open, then the magma will spill outward, flowing downhill, much like water. As soon as this super heated rock touches surface air it immediately cools back into solid rock. Eventually this rock will again plug the hole in the end of the vent, and the process begins all over again.

To Make a More Permanent Volvano:

Supplies:
1 Empty Toilet Paper Roll
10 lengths of string about 18-24 inches in length each
1 large paper plate
Plaster of Paris
2-4 Roll of Gause
Warm Water
Tape
Paints
1 mini plastic bowl (I used a washed out cup from the cinnamon rolls, the one the frosting comes in) < br/> Spray Sealant (optional)

Process:

  1. Cut 4 small slits on the bottom of the tp roll, very small ones, then bend the pieces out until you have 4 'feet'
  2. Tape these feet to the middle of your paper plate
  3. Cut about 12 evenly spaced tiny cuts along the top edge of the tp roll.
  4. Tape one end of one piece of string to the bottom edge of the plate, wrap the middle of the string between 2 slits on the top of the roll, then tape the other end under the edge of the plate. Try to make the string go to a slight diagonal.
  5.  Repeat step 4 until you have a nice structure for a Strato-volcano. (you'll use all if not most of your string.
  6. Cut a roll of Gause into roughly 8 inch strips.
  7. Mix some of your plaster with water. I do this in small sections because plaster dries crazy fast, and you need to move fairly quickly.
  8. Dip a section of Gause into the plaster and lay it over your structure, making sure not to seal off the top hole, until the whole thing (even bottom edge) is covered in a nice thick layer.
  9.  Allow it to dry completely. You can do a couple of layers until you have a solid volcano
  10.  Allow it to dry, then paint as desired
  11. You can chose to seal it with a spray sealer if you think the kids will want to cause repeated eruptions (sealer will prevent the sides from getting sticky once the 'lava' starts flowing).
  12. Fit tiny cup into the top of your volcano, this is where you'll put your chemical mixture.

Tuesday, July 17, 2012

Experiment 11: Floating Water

Experiment 11: Water Pressure vs. Air
This is another experiment that doubles as a magic tric. Amaze your family and friends with this experiment!

Supplies:

1 plastic bottle with a top (it can be a 16 oz-2 liter)
Water
Sharp knife or drill (CAUTION!!)
Sink or bucket

Process:

1) have an adult use the sharp knife or drill to make tiny holes along the bottom underside of the bottle. If using a bottle that has 4 little feet (small protrusions) then put one hole in the bottom of each; if your bottle is flat edged n the bottom, then just make 4 equally spaced holes
2) fill the bottle about 3/4 of the way full with water.
3) secret cap on tightly
4) Lift up bottle and be amazed that none of the water leaks out of the holes.
5) holding bottle over sink or bucket tips slightly and watch the water come out of the holes.

Explanation:

Water can only leak out of the holes when air can pass into the bottle via the holes. See inside every object is a constant # of molecules. I an empty bottle the bottle is actually filled with air. If the bottle is filled with water the air is pushed out through the 'mouth' of the bottle. When holding a bottle upright, the air in the bottle goes toward the top the water, toward the bottom. In effect, the water prevents more air from entering the bottle through the small holes - so the water is acting as a plug! When you tip the bottle even slightly, some of the water molecules shifty off of the openings, ever so briefly. This allows some air to enter the bottle and some water to exit the bottle. But it looks like magic to have the water not fall down out of the holes!

Experiments 8-10: Playing with Gas Pressure

The next 3 experiments all deal with gas pressure. They are among my kids favorite experiments - but, as boys, anything exploding or seeming like magic will always be a hit!

Experiment 8: Exploding Soda

CAUTION: you'll want to do this outside away from your house, as it makes a fantastic mess.

Supplies:
2 liter bottle of soda unopened 1 package of mint mentos

Process:

1) set the soda bottle in a wide open space and carefully open the top. (don't shake up the soda as you want as much of hte carbon dioxide to remain in the bottle as possible)
2) this is the tricky party. You'll want to drop at least 5 mentos into the soda at the same time. I stacked the mentos carefully so they could drop, one right after the other into the bottle.
3) duck and run! The soda will shoot up about 15 feet into the air!

Explanation:

Soda is backed with carbon dioxide, that's what all the fizz is about. A mento may seem smooth on the surface, but in actuality the entire surface is pitted with hundreds of microscopic holes. When they are dropped into the soca much of the carbon zooms through these holes, building up the gas pressure to explosive levels, as the pressure inside the bottle becomes greater than the air pressure outside, the liquid seeks to go where there is less pressure, outside the bottle. This is a similar concept to releasing a blown up balloon - it will zoom around as the pressure within the balloon is rapidly released.

Experiment 9: the Coin Launcher

Supplies:

1 small bottle of soda, empty (16 oz is a good size)
1 pieces of tissue paper
1 quarters
Freezer
Safety glasses

Process:

1) put the top on tightly on the empty bottle, also place it in the freezer
2) let sit for About 30 minutes
3) observe what changes to the bottle, but leave it in the freezer so it doesn't warm
4) wrap the quarter in the tissue paper
5) get the paper wet
6) with the bottle still in the freezer, remove the top and place the tissue wrapped quarter over the opening.
7) allow to sit in freezer until tissue is frozen
8) take bottle out of the freezer. Wear the safety glasses!
9) gently warm the bottle in your hands pointing away from you. Watch what happens!

Explanation:

When the bottle is frozen it shrinks as the air molecules pull toward the middle of the boodle. When the frozen tissue is in place of the top, it should maintain this vacuum. (if he coin doesnt shoot off, then the tissue dint form a good enough seal). When the bottle is then warmed the air molecules push back away from the center. This causes a change in pressure that pushes the coin away.

Experiment 10: Magic Card Trick

We actually first did this trick last spring for a local science fair. My youngest did the next two experiments as a part of his display on the awesome capabilities of air & water pressure!

Supplies

Small glass or plastic cup (it must have a rather sharp or flat rim with no bends)
Water
1 index card

Process:

1) fill the glass about 3/4 of the way full of water
2) lay the index card flat across the open end of the glass.
3) support the card with the flat of your hand as you quickly turn the cup upside down
4) remove your hand, amaze your family & friends with the fact that the card stays in place and doesn't fall!! (don't leave it too long upside down though, once the water soaks into the card enough it will destroy the seal and the water will go everywhere!)

Explanation:

The reason the card stays in place is based on 2 laws. First Newtons second law of motion: "every action has an equal and opposite reaction" and air pressure vs water pressure. (or more specifically air pressure vs the force of gravity)

Essentially the water in the cup is pushing down with the force of gravity (9.8 meters/second squared). While this force is pointing toward the ground, the air outside the cup of pushing upwards on the card. For a period of time this creates a seal between the card and the edge of the cup. Furthermore there are way more air molecules outside of the cup than there are water molecules inside the cup. This is the true reason for the 'magic'. All air molecules are trying to raise up. This means there is a pressure imbalance. It's like having a car hit a brick wall. If it is a small wall the wall will be destroyed by the car - because there are too many molecules in the car acting against the fewer molecules in the wall. But if it is a gigantic stone wall (like a concrete bridge support) then the car is the one with more damage - as there are more molecules in the wall than there are in the car.

Monday, July 16, 2012

Experiment 7: Making Rain

This experiment is fun, especially for elementary and preschoolers. We did it as a part of our study of the water cycle.

CAUTION: you must have adult supervision for this experiment as you are dealing with a stove top and boiling water. This experiment also demonstrates how temperature is one of the main factors in changing the state of matter.

Supplies:
  •  one hard covered book
  • stove top heating element
  • one small sauce pan
  • freezer
  • water
Process:

1) place your hardcover book in the freezer and allow it to sit there at least over night.
2) boil a pot of water (demonstrating evaporation)
3) once you have a cloud of steam rising from the pot, hold the book at an angle in the steam, making rain! - Watch out for your fingers! Steam is very hot!!

  Explanation:

  First in changing the states of matter: This is the approach to take with older kids who may already be familiar with the water cycle. In order to change a substance to different states of matter (liquid, solid, gas) you must apply a change in temp. A solid is a substance that has the molecules tightly packed together with stong bonds, at room temperature. A liquid is one where the molecules are spread out, some have bonds to other molecules, some are free floating. A gas is where the atoms/molecules float independantly from the other atoms, no bonds between them, rarely do they interact with the other atoms.

Water is one of the easiest to see the change in matter. If you apply heat, the liquid will evaporate, this results in steam - aka water vapor (a gas). If you apply a dramatic drop in temperature (like in a freezer) the h2o molecules will bond tightly together creating a solid (ice). Now, most children are taught these 3 states of matter at fairly young ages. But did you know there are actually 5 states of matter? The unsung heroes of matter are Plasma and the Bose-Einstein Condensiate (BEC). Plasma as a state of matter was only introduced in 1879, and the BEC was only recognized in 1995!! In a BEC the atoms are even more richly packed than in a solid. Most solids are brittle because of the way the molecules are bound (ever shattered a piece of ice?), but BEC are extremely strong, and not easy to break. A plasma is a cross between a solid and a liquid. It has properties of both.

Scientists are still hard at work on understanding matter. In fact, most scientists now refer to 'states of matter' as a Phase. For example, with water. If you start at a very low temperature you have a BEC, slowly increase the temp and youll have a solid (ice). If you slowly increase the temperature, you'll get a plasma (slushy like material, some ice, some water). Keep the temp increasing and you'll eventually get a liquid, keep the gem going and eventually you get a gas. So it is like your water has gone through different phases based on temperature. In a nutshell, matter is understood based on 2 things: temperature and the density of the molecules.

Water cycle: Did you know the amount of water found on Earth hasn't changed for billions of years? The only things that have changed are the location and whether or not the water is drinkable! The water cycle is responsible for both. It is never ending, which is why it is considered a cycle. At any given moment there are millions of gallons of water all around the globe: from oceans and seas (which contain a lot of salt); to lakes, rivers and ponds which are fresh water (low salt, but higher in other natural chemicals; to clouds, snow, ice and rain! Water is everywhere. To keep water moving about we rely on the water cycle. You see, the sun heats the surfaces of most water (puddles, rivers, oceans etc.) the only water unaffected by this first stage is water found below the ground or ice. As the sun heats the water some molecules seperate and turn to water vapor, a gas. Since water vapor is lighter than air it raises high into the sky. Way up high in our atmosphere it is very cold, the water vapor then wants to bind back to a solid, but our atmosphere is vast, so the molecules have trouble finding eachother in order to bond. Istead the bond with dust particles. This is the reason for the awesome shapes of a snowflake. Many water molecules will bind with individual dust particles, growing into ever larger snowflakes (ice). The particles might even find eachother, creating clouds. But the sun strikes these atoms as well, melting the ice back to water, which is heavier than air so it falls back to the ground as rain. (in winter the snow/ice particles grow until they are too heavy to remain aloft and they fall as snow or ice!). Once the rain is on the ground it flows down stream, back to the oceans, rivers lakes, etc. Happy learning!!

Sunday, July 15, 2012

How to handle the epic fail

We have all been there. Our curriculum looks beautiful, we have all the supplies, the kids (and we, the teachers) are jonesing to jump in and go full steam ahead. So we start...within an hour the kids are antsy, not following directions, not completing work we know they are capable us. Argh! Is there anything more frustrating? Inevitable we keep trudging along, even though we begin to dread the start of school each day. We might even toy with the idea of putting the kinds in PS just to get a break! so, I thought I would write a little on using those epic fails to your advantage. Don't lose hope. Ever hear the saying, " you must kiss a hundred frogs before you find a prince"? This is how I tell newbies to approach HS. This is also one of the main reasons I'm against spending a load of $$ right away. Because you know what? Everyone learns differently. Not only that, but a child's learning style might evolve over time. So even if you get a curriculum that is similar to their style from the previous year, it may no longer work. There are a few things to keep in mind to stave off frustration: 1) Don't beat a dead horse. (I'm working metaphors for all they are worth in this article! Lol) If something isn't working for 1 week then STOP. It may just mean you all need a little break. So you can try again in a couple of weeks. If it is again an epic fail after another week, then let it go. Find another approach, or it may just mean they are not ready for the information (see point 3 for developmental milestones). 2) What looks good to you may be an epic fail for them. I remember when I first began to HS, I planned how I wished I had been taught - I learn by writing things down. Doing a lot of copy work, worksheets, etc. Epic fail. My oldest is a visual learner. It was pointless to have him do a ton of writing assignments. Sure I might be able to browbeat him into eventually completing the work, but he wouldn't retain any of the information. This was probably more frustrating than him just not completing the work to begin with. We'd spend literally hours on one assignment, with a lot of yelling to keep things on track, and finally (FINALLY) the work is finished and I ask, so what is blah? And he would stare at me uncomprehendingly. Even if I promoted to get the right answer, I'd still get nowhere. Finally a lightbulb went off above my blonde head - maybe he doesn't learn from writing things out? Duh. Lol. I had a whole school room devoted to notebooking that I had to donate. But even this fail is a step in the right direction. I can now eliminate any curriculum tool that is based on writing. So instead of notebooking, we changed to Lapbooking - which still has some writing involved, but is much more visually stimulating. My point here is to be aware of your students learning styles, even if it is completely counter to your own. Then try to find tools based in that style. 3) Get ready for a change! Yup. You did your year of struggle, finally found a curriculum that works, you go with it. It might even work for a few years, then it all starts to fall apart. Why? Well children are growing and changing. So too do their learning styles. Here is my own break down of typical styles-to-ages. Bear in mind every child is different, so your child might be different, this is just a guide. Pre-k - 2nd grade = Kinetic: it's all about the hands on learning, manipulatives, getting their senses involved. This is because they are just coming out of the toddler years, so their mind is still in tune with using eir senses to acquire information. If a toddler sees something new, they generally touch it, put it in their mouth, etc. well these early grades are not quite that bad, but their attention spans are still pretty short and they a not yet trained to acquire information through reading. Even with an early reader/writer, you'll want to have curriculum that is heavy on the kinetic learning. 2nd-4th = Visual: it's all about creating that picture in their mind. If you want to learn ancient history, they will remember more if you make it like a story where they can see the visual image, like a movie, in their head. They can learn a lot through short films and discussions. They are just beginning to become aware of themselves as individual entities. They still might enjoy manipulatives, but you can begin trickling in more complex content as long as you do it in a way that creates the visual in the mind. 4th-7th = Combo: these learners need a variety of tools - they can acquire information from reading and writing, they can learn through the visual, etc. they need a little of everything. Here it's time to begin cutting the apron strings. These students do much better with a bit of independance. They can make better choices. So I advise getting an outline together of what you want covered then pulling together resources that meet a variety of requirements and letting the student choose which sparks their interest. 8th-Graduation = Independant Study/Audio: here learning is really all up to them. Whether it be digesting the information delivered from a lecture, A documentary or through literature, they take whatever techniquest they have developed ov time, to process and retain information. They should also be capable of not just regurgitating information (memorization) but changing information into their own words. No matter your students personality or age, there will come a time when choices must be made. An unfortunate result could be the epic fail. But don't let it get you down. Being a HS educator is as much a learning experience as being an HS student is. We are all on a path of self discovery, growth and learning. Happy learning!

Experiment 6 - ivory soap

Talk about cool chemistry, in this experiment you can see the affect of microwaves, it is super exciting!

Supplies:
A bar of Ivory soap
Microwave Paper or ceramic plate

Process:
1) unwrap the soap and place it in the center of the plate
2) set the plate in the microwave and set the time to 2 minutes
3) Press start and let the time tun out
4) Once the microwave stops, CAREFULLY remove the plate from the oven and allow to cool for about 2 minutes until it is cool enough to handle the soap.
5) hold the soap in your hand, how does it feel?

  Explanation:
The microwave heats the soap causing it to soften. The microwaves then excite the water and air molecules in the soap. This causes the soap to lose its shape and expand as the molecules try to move in opposite directions from eachother. Evaporation of the water causes more air pockets. Since the soap has softened, and the molecules have moved away from eachother and caused air pockets, the result is a foam like substance. Remember there are 3 forms of matter: solid, liquid and gas. In a gas the molecules are very far apart, very rarely do they interact with each other, there are no bonds holding them together. In a liquid, some of the molecules are bound, some are not. In a solid, all the molecules are tightly bound together. In this experiment we are changing the state of matter from a tightly bonded solid to a more pliable liquids material.

Saturday, July 14, 2012

Experiment 5: Plastic Milk

Ok, I love chemistry! I think is is so fun, and educational, when you can see with your own two eyes some substance radically change. In this experiment you can change a glass of milk into a plastic! (no joke!)

Supplies:
  • 1 glass of full cream milk (I also suggest doing this with a variety of creams and milks if you can afford it - whipping cream, whole milk, etc, to see how it affects the results)
  •  vinegar
  • eye dropper
  • wooden/plastic spoon
  • microwave (or a bowl of freshly boiled water)
Process:
  1. fill a glass about 3/4 of the way with the whole cream milk
  2. microwave the glass for about 1 minute until milk is warm
  3. Fill the eye dropper with vinegar
  4. stir milk with spoon as you slowly add the vinegar
  5. Hold your hand over a sink (MAKE SURE THE MILK ISN'T TOO HOT!) pour the 'milk' over your hand, catching the plastic!
Explanation:
The cream in the milk contains a chemical called casein. When you add the vinegar, the casein separates from the rest of the milk. The molecules on casein are loosely bonded together in a chain, making form on plastic! Casein is a bonding protein found in many foods that contain Phosphoric Acid. It really is also included in may products like plastic, paint, etc. Therefore, it can be found in two forms: edible and technical. Casein is similar to salt in that it doesn't change form when added to a substance. I this experiment we can see that, as we are just separating those molecules from the rest of the molecules in the milk. Casein is a protein and acts as a binding agent. So it is an important part of making cheese and yogurt. On a side note: there have been studies that show a link in adverse effects of casein in those with autism. Many with autism have food sensitivities, similar to allergies. So families will avoid dairy, thinking they are avoiding the allergy, not realizing it is the casein (found in various other foods) that might be the culprit.

Experiment 4: Eddy Currents

As many of you know I used to be an aeronautic engineer. I helped design holographic inspections for the rockets for NASA and I also worked with Eddy Currents, used as a non-destructive testing tool. You see, there are often microscopic scratches on the surfaces of jet engine parts.the vibrational forces exerted on an engine in use, and over time, can cause these scratches to propagate into actual cracks. In order to prevent catastrophe, engine makers use ultrasound and eddy currents to detect these microscopic cracks, so they can be sanded away. Eddy currents are very cool. Anyone with a strong magnet can see them in action. So I thought I'd include an experiment that demonstrates this phenomena - which is great for kids of all ages!

What you'll need:
  •   A strong magnet
  • A section of copper pipe
  • A section of some other material pipe (or even a toilet paper/paper towel roll)
Process:
  1. Stand thepipes up on end, or your student can hold them in their hand, vertical.
  2. hold the magnet over the opening on one end of the non-copper tubing
  3. let the magnet drop, it will fall right down at the forces of gravity
  4. now hold the magnet over the opening at one end of the copper tubing
  5.  let the magnet go, watch what happens!
Understanding the experiment:
The magnet will float in the copper tube. This is the result of a specific form of Electro-Magnetic force called the Eddy current. As you know, copper is a conductor of electricity. When the magnetic field interacts with the surface of the tube, the metal begins to generate its own magnetic field/current. This was discovered by a scientist by the name of Michael Faraday. The magnetic field created in the metal opposes the one surrounding the magnet. What happens when the same polarized ends of 2 magnets interact? They push eachother away. The same is true here. The magnetic field generated in the pipe is calle the Eddy Current. This all falls within the Physics law called Lenz's Law. Older kids can research Michael Faraday and the Russian physicist Heinrich Lenz. For another simple experiment demonstrating Lenz's Law, check out the Swinging Magnet experiment http://www.ndt-ed.org/TeachingResources/NDT_Tips/LenzLaw.htm

Experiment 3: Acids & Bases

For today's experiment we will be doing some kitchen chemistry. It's super easy and fun for kids of all ages! Experiment - Determining pH

What You Need-
  • Some Red Cabbage
  • Lemon Juice,
  • Baking Soda,
  • Cola,
  • Water,
  • Vinegar
  • Oil,
  • milk of magnesia (if you have it on hand)
  • PH chart (like the one found http://www.elmhurst.edu/~chm/vchembook/184ph.html )
  • Medium sized bowl
  • Grater
  • Strainer
  • Clear cups
  • Some plastic containers
Process:
  1. grate some cabbage into the medium sized bowl
  2. Cover cabbage with cold water and allow it to sit for 45 minutes.
  3. Strain the water mixture into a plastic container
  4. Pour an equal amount of juice into the cups
  5. Add 1 tsp to all but one of the cups. Mix. This should turn the mixture blue, as baking soda is a base.
  6. Add lemon juice to one of the blue cups, a little at a time. How much do you need to add before bringing the color back to normal?
  7. repeat #6 for each of your other liquids. One in each cup. If the liquid remains blue, then your substance is a base. But you should notice different liquids require different amounts to change the color back to normal.
  Reasoning:
We use red cabbage because the chemical makeup of the juice allows it to dramatically change color when mixed with other substances. This makes it easy to see the alkaline (pH) differences. Now, a little about pH - when you mix an acid and base, they cancel eachother out, neutralizing them. There are many neutral substances though, water and milk, for example. So, what is pH? Really all acidity is is a measurement of Hydrogen ions in a substance. They more hydrogen molecules in a substance the higher the acidity. Any substance added to water that causes an increase in the concentration of hudrogen molecules is considered an Acid. And substance added to water that decreases the concentration is considered a Base. The lase category of substances, as those that help resist changes in pH, these substances are called Buffers. As they help protect the water from changing pH level. Bonus: Now that you know which substances are acids. Think of which one would best remove the grime on an old penny. The substance with the highest acidity level. This is the one that you needed to add less of to turn the cabbage water back to its original color. Drop a penny in an old cup, add a bit of your acid ad watch it work!

Experiment 2: Inertia & Tensile Strength

I love inertia, it's so fun to play with! This experiment will greatly get these kids thinking. Have them brainstorm as a team to come up with a hypothesis (prediction) of what they think will happen and WHY. We have experiment journals, here the kids keep track of the supplies, process, hypothesis, and results from all our daily experiments. Most of our experiments use things you should have readily available around the house.

  SUPPLIES:
  • Water bottle (or small soda bottle)
  • 4 Pieces of string about 40 cm long (cotton is best, but you can judge the tensile strength of various fibers in another experiment)
PROCESS:
  1. tie one end of 2 pieces of string around the neck of the bottle
  2. tie the other end of ONE of the strings onto something solid like a railing, so the bottle will hang down
  3. holding the other end of the other string in your hand. Pull slowly. Where will the string break?
  4. repeat steps one-three, but this time jerk the string quickly. Where does it break now?
Understanding Inertia: Inertia is a part of Newtons First Law of Motion. "An object at rest wants to stay at rest, whereas an object in motion wants to remain in motion." Inertia is the measurement of how hard it is to get an object to change motion. For instance. One example of inertia would be how hard do you have to push the breaks to stop a car that is rolling downhill in neutral. Or, an example for kids, how much pressure do you have to apply to get your matchbox car to zoom across the room. In this instance. Inertia is proven because, in effect, the motion of your arm wants to continue on, but it comes to the length of the string. In order to maintain inertia, it breaks the string.....now, why do you think they broke in different places?

Understanding Tensile Strength: Tensile strength refers to The amount of stretching strength a material has before breaking. For instance, if you have a waterski rope, and try to tow a house with it, it will break because the force/weight of the object exceeds the tensile strength of the rope. But if you tow a boat with a thick chain, then it will probably be ok, because a steal chain has a high tensile strength. But if you add in inertia and momentum, then it decreases the tensile strength of an object because of Newtons Second law "Every action has an equal and opposite reaction"" so as you pull left an equal force yanks the rope left. The faster you pull the greater the force/momentum, the smaller the tensile strength...get it?

Wednesday, July 4, 2012

Experiment 1: Drinking Water from Salt Water

I don't know about where you are, but it's been hotter than Billy Blue Blazes here. (though, now I'm curious about who Billy Blue is and who set him on fire....lol). One of the ways we try to bear the heat is through doing experiments. They can be fun, cheap, easy and educational! Drinking water is becoming more and more scarce the world over as fresh water supplies are evaporated due to global warming and droughts. You can use the following resources to do some research on the current water shortage situation: http://drinkingwaterz.com/2369-shortage-of-drinking-water.html http://whyfiles.org/131fresh_water/2.html

One of the things that has intrigued scientists from the time we emerged from the caves, was how to take the plentiful salt water of the seas and oceans and make them palatable for drinking. Ok, onto the experiment, this is a small scale version of one of the methods scientists are evaluating.

  Supplies:
  • 1-2 TBS table salt
  • bowl
  • 3 cups water (tap water is fine)
  •  small bowl or coffee cup
  • stone
  • thick plastic wrap
Procedure:
  1. pour watere into the larger bowl
  2. mix salt into the water until it is dissolved
  3.  place the small bowl or cup into the water CAREFULLY, you do not want to let any of the water to flow ov the sides of the cup.
  4. Place the stone in the center of the plastic wrap, so at the wrap angles down into the cup a bit.
  5. carefully place the bowl in the sun
  6. wait several hours. You should see water droplets on the inside of the plastic wrap dripping into the cup.
  7. after a few hours allow student to taste the water in the cup - it won't be salty!
What happened:
The water from The bowl evaporated, condensing on the underside of the plastic wrap (which is why heavy duty plastic wrap is so important, lesser quality plastic wrap will allow the water vapor to escape and leave the cup empty.) salt doesn't evaporate, so essentially the evaporation process separates the water molecules from the salt ones.