Friday, September 9, 2016

Science Quest # 12 - Plate techtonics

Today we are going to do some online gaming before we get started!

Go to  the following website and play the slip- slide- collide game!

http://www.open.edu/openlearn/science-maths-technology/slip-slide-collide

Interested in trying it yourself?

Grab a baking pan (with the most lip that you can find), some oobleck (perhaps from #7?) or a tub of frosting, some foam card stock (simulating the continental plate) and two heavy flat objects (like tiles or small plates) (simulates the oceanic plates)

Step 1:  put the oobleck or the frosting into the pan
step 2: place 2 heavy flat objects into the pan - on top of the goo from step 1 - 
            place them side by side.  Then, while pressing down slightly, move them apart.  The goo underneath should be exposed and will push up where the plates are separated.  This demonstrates how the magma will come to the surface when the plates are moving apart at divergent boundaries.  
In a divergent boundary the plates move apart from each other.

Step 3:  reset to the beginning
Step 4: Place one heavier plate next to a piece of lighter foam card.  Gently push the two pieces together until they overlap so that the foam is on top of the heavier plate.  What happens?
In a convergent boundary the plates move toward one another.

Step 5: reset to the beginning
Step 6: place two pieces of light material next to each other.  Push the pieces in opposite directions perpendicular to the direction of the junction (so one north and one south, rather than toward or away from each other).  What happens?
This is a transform boundary- these move alongside each other.
   
Which type of boundary creates volcanoes?  

Which type of boundary is the San Andres fault which runs alongside California in the United States?





answers:
Volcanoes are caused by divergent boundaries
The San Andreas fault is caused by a transform boundary.

Friday, September 2, 2016

Science Quest # 11 - Electroplating: Copper-Plated Key

Electroplating: Copper- Plated Key (Advanced & parental help/supervision required!)

Electroplating: Copper-Plated Key
Electroplating uses a form of electrolysis in which the electrodes play a bigger role than just conducting the current. Using electricity, you can coat the metal of one electrode with the metal of the other!  Jewelry and silverware can be silver- or gold-plated, while zinc is often used to coat iron to protect against rust. Professional electroplating requires specialized chemicals and equipment to make a high-quality coat, but in this project you can try your hand at a simple procedure that will transfer copper to a brass key. (Adult supervision and chemical safety equipment required.)

What You Need:

What You Do:

  1. Prepare the key for copper-plating by cleaning it with toothpaste or soap and water. Dry it off on a paper towel.
  2. Stir copper sulfate into some hot water in a beaker until no more will dissolve. Your solution should be dark blue. Let it cool.
  3. Use one alligator clip to attach the copper electrode to the positive terminal of the battery (this is now the anode) and the other to attach the key to the negative terminal (now called the cathode).
  4. Partially suspend the key in the solution by wrapping the wire lead loosely around a pencil and placing the pencil across the mouth of the beaker. The alligator clip should not touch the solution.
  5. Place the copper strip into the solution, making sure it doesn't touch the key and the solution level is below the alligator clip. An electrical circuit has now formed and current is flowing.
  6. Leave the circuit running for 20-30 minutes, or until you are happy with the amount of copper on the key.

What Happened:

The copper sulfate solution is an electrolyte that conducts electricity from one electrode to the other. When the current is flowing, oxidation(loss of electrons) happens at the copper anode, adding copper ions to the solution. Those ions travel on the electric current to the cathode, where reduction (gain of electrons) happens, plating the copper ions onto the key. There were already copper ions present in the copper sulfate solution before you started, but the oxidation reaction at the anode kept replacing them in the solution as they were plated onto the key, keeping the reaction going.
This project has many variables, including the cleanness and smoothness of the key, the strength of the copper sulfate solution, and the strength of the current. If a black soot-like substance starts forming on the key, your solution is not strong enough for the current. Take the electrodes out and add more copper sulfate. When you put them back in, make sure the anode and cathode are as far apart as possible.
There are lots of projects you can do with electroplating! One fun idea is to use a flat piece of brass as your cathode and draw a design on it with an oil-based marker. The copper will not bond where the marker is. After you're done plating it, you can use acetone (or nail-polish remover) to wipe off the marker, leaving a design of the brass showing through the copper. You can use a little metal polish to make the copper shiny, if you want.
You may want to try this simple copper-plating experiment that doesn't use electrolysis and requires only household materials.

Friday, August 26, 2016

Science Quest # 10 - Cartesian Diver




How can scuba divers and submersibles dive down into the water and then come back up? Find out with this easy project.
Make a Cartesian Diver

What You Need:

What You Do:

1. Fill a glass with water and put the medicine dropper in it. Suck enough water into the dropper so that it just barely floats - only a small part of the rubber bulb should be out of the water. This is your diver, and it has neutral buoyancy. That means the water it displaces (pushes aside) equals the weight of the diver. The displaced water pushes up on the diver with the same amount of force that the diver exerts down on the water. This allows the diver to stay in one spot, without floating up or sinking down.
2. Now that your diver is ready with enough water inside to give it neutral buoyancy, fill the soda bottle all the way to the top with water. (You don't want any air between the water and the cap.) Lower the medicine dropper into it and screw the cap on tightly.
3. Squeeze the sides of the bottle. What happens? The diver sinks. Let go of the bottle and it will float back up. Why does it do this? Watch carefully as you make it sink again - what happens to the air inside the dropper?
As you squeeze the bottle (increasing pressure) the air inside the dropper is compressed, allowing room for more water to enter the dropper. (You'll see the water level in the dropper rise as you squeeze the bottle.) As more water enters, the dropper becomes heavier and sinks. Practice getting just the right amount of pressure so your diver hovers in the middle of the bottle.
Submarines and submersibles have ballast tanks that fill up with water to make them dive. When it's time to surface, air is pumped into the tanks, forcing the water out and making the sub float to the top. Read more about submarines here. Scuba divers wear heavy belts of lead to make them sink in the water, but they also have a buoyancy compensator. This is a bag that they inflate with air from their oxygen tank. When it is inflated, it causes them to float up to the surface. While underwater they'll put just enough air in the bag to keep them from floating or sinking.
Of course, most subs and scuba divers are diving in salt water. Try your diver again in a bottle of salt water. Is there any difference in the way it works? Do you need to start out with more water in the dropper than you did before? Remember salt water is denser than fresh water!

Friday, August 19, 2016

Science Quest # 9 - electric motor

Simple Electric Motor  
(photos for below found on linked site)

Updated on Sep 09, 2013

Energy comes in many forms. Electric energy can be converted into usefulwork, or mechanical energy, by machines called electric motors. Electric motors work due to electromagnetic interactions: the interaction of current (the flow of electrons) and a magnetic field.

Problem

Find out how to make a simple electric motor.

Materials

  • D battery
  • Insulated 22G wire
  • 2 large-eyed, long, metal sewing needles (the eyes must be large enough to fit the wire through)
  • Modeling clay
  • Electrical tape
  • Hobby knife
  • Small circular magnet
  • Thin marker

Procedure

  1. Starting in the center of the wire, wrap the wire tightly and neatly around the marker 30 times.
  2. Slide the coil you made off of the marker.
  3. Wrap each loose end of the wire around the coil a few times to hold it together, then point the wires away from the loop, as shown:
What is this? What is its purpose?
  1. Ask an adult to use the hobby knife to help you remove the top-half of the wire insulation on each free end of the coil. The exposed wire should be facing the same direction on both sides. Why do you think half of the wire needs to remain insulated?
  1. Thread each loose end of the wire coil through the large eye of a needle. Try to keep the coil as straight as possible without bending the wire ends.
  1. Lay the D battery sideways on a flat surface.
  2. Stick some modeling clay on either side of the battery so it does not roll away.
  3. Take 2 small balls of modeling clay and cover the sharp ends of the needle.
  4. Place the needles upright next to the terminals of each battery so that the side of each needle touches one terminal of the battery.
  1. Use electrical tape to secure the needles to the ends of the battery. Your coil should be hanging above the battery.
  2. Tape the small magnet to the side of the battery so that it is centered underneath the coil.
  1. Give your coil a spin. What happens? What happens when you spin the coil in the other direction? What would happen with a bigger magnet? A bigger battery? Thicker wire?

Results

The motor will continue to spin when pushed in the right direction. The motor will not spin when the initial push is in the opposite direction.

Why?

The metal, needles, and wire created a closed loop circuit that can carry current. Current flows from the negative terminal of the battery, through the circuit, and to the positive terminal of the battery. Current in a closed loop also creates its own magnetic field, which you can determine by the “Right Hand Rule.” Making a “thumbs up” sign with your right hand, the thumb points in the direction of the current, and the curve of the fingers show which way the magnetic field is oriented.
In our case, current travels through the coil you created, which is called the armature of the motor. This current induces a magnetic field in the coil, which helps explain why the coil spins.
Magnets have two poles, north and south. North-south interactions stick together, and north-north and south-south interactions repel each other. Because the magnetic field created by the current in the wire is not perpendicular to the magnet taped to the battery, at least some part of the wire’s magnetic field will repel and cause the coil to continue to spin.
So why did we need to remove the insulation from only one side of each wire? We need a way to periodically break the circuit so that it pulses on and off in time with the rotation of the coil. Otherwise, the copper coil’s magnetic field would align with the magnet’s magnetic field and stop moving because both fields would attract each other. The way we set up our engine makes it so that whenever current is moving through the coil (giving it a magnetic field), the coil is in a good position to be repelled by the stationary magnet’s magnetic field. Whenever the coil isn’t being actively repelled (during those split second intervals where the circuit is switched off), momentum carries it around until it’s in the right position to complete the circuit, induce a new magnetic field, and be repelled by the stationary magnet again.
Once moving, the coil can continue to spin until the battery is dead. The reason that the magnet only spins in one direction is because spinning in the wrong direction will not cause the magnetic fields to repel each other, but attract.

Friday, August 12, 2016

Science Quest # 8 - Dancing Raisins


Experiment

  1. Fill the glass with soda.
  2. Drop 10-15 raisins into the soda.
  3. Focus all of your attention on those raisins.  Are they moving?  Yes!  They’re floating, they’re bobbing up and down, they’re dancing!  
Dancing Raisins Variation
  1. Set up your drinking glasses with different types of soda.
  2. See which type of soda makes the best dancing raisins.
  3. Try using all of the same type of soda but different kinds of “dancers.”
  4. Throw in macaroni, noodles, lentils, craisins, even corn!
  5. Which combination of soda and dancers “performs” the best show?
  6. Keep experimenting until you find the best combination!

How Does It Work?

You can guess why this is an extremely popular activity among elementary teachers.  We recommend that you play some dance music and encourage the kids to join in with the raisins while you learn about the science behind the dance.
The raisins will bob up and down for several minutes.  This “raisin dance” is captivating to watch.  Since the surface of the raisins is rough, tiny bubbles of carbon dioxide gas are attracted to it.  These bubbles increase the volume of the raisin substantially, but contribute very little to its mass.  As a result, the overall density of the raisin is lowered, causing it to be carried upward by the more dense fluid surrounding it. 
                                                                    
Archimedes’ Principle states that the buoyant force exerted on a fluid is equal to the weight of fluid displaced.  Since the raisins now have a greater volume, they displace more water, causing the fluid to exert a greater buoyant force. The buoyant force of the surrounding fluid is what pushes the raisins to the top.
Once the raisins reach the top, the bubbles pop upon exposure to the air.  This makes the raisins more dense, causing them to sink.  As more bubbles adhere to the raisins, the density of the raisins decreases and they rise to the surface again. This experiment very clearly shows that an increase in volume (as long as the mass increase is negligible) will lead to a decrease in density.  The bubbles that attach themselves to the raisins are like little life jackets that make the raisins more buoyant by increasing their volume.
If you put the raisins directly in the bottle and replace the cap, eventually the raisins will stop dancing. This is because carbon dioxide gas is prevented from leaving the bottle. As a result, pressure builds up in the space above the fluid. This pressure is transmitted throughout the fluid, and the bubbles cannot grow as large. The volume of the raisins cannot increase enough to lower their density to the point where they will rise.  When the cap of the bottle is removed, the bubbles grow larger, and the raisins resume the cycle of their “dance.”
The same scientific principles are at work when a child uses a set of inflated “floaties” or an inner tube at the pool. The volume of the floaties increases the child’s volume considerably.  The mass of the floaties, however, is very small.  The overall effect is to lower the density of the child wearing the floaties to less than that of the pool water, so that the child can float.  Deflating the floaties (don’t try this with someone who can’t swim!) would reverse the process and cause the person to sink.

Friday, August 5, 2016

Science Quest # 7 - Oobleck

Oobleck!  

Oobleck is a classic science experiment that's perfect for entertaining both kids and adults. If you haven't seen it in action it's very fascinating stuff and before too long you'll have your hands covered with it, happily making a mess that can be washed away with water.

Oobleck is a non-newtonian fluid. That is, it acts like a liquid when being poured, but like a solid when a force is acting on it. You can grab it and then it will ooze out of your hands. Make enough Oobleck and you can even walk on it!

Oobleck gets its name from the Dr. Seuss book Bartholomew and the Oobleck where a gooey green substance, Oobleck, fell from the sky and wreaked havoc in the kingdom. Here the Oobleck will be made in a bowl and will likely make a mess, but only because you can get carried away playing with it.

All you need is corn starch and food coloring and the food coloring is optional. 

Recipe:
- 1 cup water
- 1.5-2 cups corn starch
- a few drops of food coloring of your choice

MIx it
Start with the water in a bowl and start adding the corn starch to it. You can use a spoon at first, but pretty quickly you'll be moving on to using your hand to stir it up. 

When you're getting close to adding 1.5 cups of the corn starch, start adding it in more slowly and mixing it in with your hand. The goal is to get a consistency where the Oobleck reaches a state that is the liquid and yet solid.

Sometimes you will need more cornstarch. If so, keep adding more than the initial 1.5 cups. If you add too much, just add some water back into it. You will have to play with it to see what feels appropriately weird.

Add food coloring

Now that the Oobleck is just right, it's time to add some color. We save this step for later because it's a fun challenge to stir in the food coloring. You will have to slowly mix the Oobleck around to get it thoroughly mixed.

Play with it!  

No go ahead and play with the Oobleck. That's the point of all this and you can find lots of tricks to try out. Here's a short list:

- Grab a handful, squeeze it, and let it ooze out your fingers.
- Make a puddle and quickly drag your fingers through it.
- Put it into a plastic container and shake it or quickly bump it against a table.
- Jab at the Oobleck and then slowly let your finger sink in.
- Put it on top of a subwoofer and play some low frequencies at high volume (tough to set up, but worth it)

Have fun and be sure to wash it all off in the end.

Friday, July 29, 2016

Science Quest # 6 - Soft shelled eggs

Soft Shelled Eggs

(taken from kidzone)

© Contributed by Leanne Guenther

What you need:

  • 1 egg (hard boiled is less messy if you accidentally break it, but you can use a raw one)
  • 1 cup vinegar
  • clear jar or glass
  • Optional:  Soft Shelled Eggs Printable Activity Sheet
  • Directions:

    • Pour 1 cup of vinegar into jar
    • Add the egg
    • Record what you see (bubbles rising from the egg)
    • Leave the egg in the vinegar for one day.
    • Remove the egg and feel it.
    • Record your observations (the egg shell will be soft)
  • What happened:

    Eggs contain something called "calcium carbonate".  This is what makes them hard.
    Vinegar is an acid known as acetic acid.
    When calcium carbonate (the egg) and acetic acid (the vinegar) combine, a chemical reaction takes place and carbon dioxide (a gas) is released.  This is what the bubbles are made of.
    The chemical reaction keeps happening until all of the carbon in the egg is used up -- it takes about a day.
    When you take the egg out of the vinegar it's soft because all of the carbon floated out of the egg in those little bubbles.

    NOW TRY THIS:

    Leave the same egg sitting out on the table for another day.
    Now feel it again.
    It's hard!
    The calcium left in the egg shell stole the carbon back from the carbon dioxide that's in the air we breath.
    - OR -
    If you were using a raw egg, once the shell has softened, you can place the egg in water and it'll absorb and expand via osmosis until the shell finally bursts.  (Thanks to James for sharing this tip!)

    OR THIS:  (KNOTTED BONES)

    What makes our bones hard?  That's right!  Calcium carbonate -- the same thing that made the egg shells hard.
    Optional:  Knotted Bones Printable Activity Sheet
    Take some thin chicken bones and drop them in vinegar for a day.  Take them out and they'll be soft just like the egg shells were.
    Now you can tie them in a knot, just like a piece of string.
    Leave them sitting out on the table and they'll get hard again!
    Take them to school for sharing time and see if your classmates can figure out how you did it (or do this at school and take them home to stump mom and dad!)