Saturday, March 29, 2014

Filling a Vacuum (Playing With a Syringe)

Its been far too long, but the Science Kid was on a little vacation.  But she's back and ready for SCIENCE!

A vacuum is simply an absence.  No water; no air; no nothing!  Even deepest darkest space isn't a vacuum.  As one would travel through interstellar space, the hydrogen atoms, moving at only a few degrees above absolute zero, would bump into your spaceship and cause some serious problems.  Even though a vacuum is only a theoretical construct, we can get pretty darn close here on planet Earth.  When you drink through a straw, you are creating a vacuum.  When you kiss someone on the cheek, you are creating a vacuum.  When you clean your get the idea.
By removing the air from an enclosed space, a virtual vacuum is created.  We can do this with our mouth, but that takes quite a bit of effort.  We can use a pump, but requires some very strong seals and lots of people power.  To create a vacuum in our lab today, we used a 1mL syringe.

Note:  Most pharmacies will carry a variety of syringes.  They are common for giving babies medicine, among other things.  You can even sweet talk your doctor or vet into giving you a few to play with.  However, I can't stress this enough.  Make sure that your SK knows that any syringes found ANYWHERE except the lab are not for science.  This is probably a bigger issue for City SKs than Suburban or Rural SKs, but you never know...

SK asked if you could wear a hat in the lab..That was a great idea!  It is very important to keep our hair (and the sun?) out of our eyes, so Goggles and hat it is.

We started with a simple bowl of water.  We talked about what was in the syringe when we pulled out the plunger.  The first answer was nothing, of course.  But we pulled the plunger out with the tip of the syringe on SKs hand.  When we pulled it off, it made a popping sound!  She determined that if the plunger was pulling something, it would be pulling in the air.  If the air goes in when we pull, the air comes out when we push.  We had some fun blowing little puffs of air into each other's faces!

Next, we used our bowl of water.  First, we pushed the air into the water and it made bubbles!  Without prompting, SK pulled in the water instead of the air, but put it right back into the bowl.  I'm not sure if she saw the water go in, so I took my syringe, pulled in the water and squirted it into the bowl from above.  Without missing a beat, she gave it a try.  We talked about how the water stayed inside of the syringe, even when it was out of the bowl; the air was pushing the water at the tip.  The only way to to get the water out was to push the plunger.
After we played a bit, SK wanted food coloring...again.  So we put in some drops, stirred, and kept squirting each other!

This was a pretty easy experiment to put together.  What sorts of modifications could we make?
  • The food coloring was a good addition, because we could more easily see the water in the syringe.
  • Straws could be used to compare the process to the syringe.  The old finger on the end of the straw operates on the same property.
  • Even a water-squirter as used in a swimming pool could work!  Unfortunately, March in Chicago isn't a good time for water sports.
What sorts of things did you do with your SK?

Saturday, March 8, 2014

Conductive Materials (aka Making a Bulb Light Up!)

I made the mistake of trying to Science after a LONG nap on a partially empty tummy!  Lesson learned; after dinner is just as good of a time for Science Saturday as any...

First, the science.

This week, I shouldn't be straining anyone's brain.  Metals have a property in common; they give up their electrons pretty easily.  In a dry cell battery (think AA, AAA, C, etc.), there are two metals.  Each gives up its electrons differently.  Some do it more easily than others.  This difference is called electronegativity.  We take advantage of this difference by separating the two metals and forcing the electrons to move through wires that we connect from one side to another.  As the electrons move, we can put something in the way, which causes an energy change.  The most simple version of this is a light bulb filament.  As the electrons move through the filament, they encounter resistance, and give off light and heat.  Ultimately, the electrons return to the other side of the battery.  The battery 'dies' when all of the metal on one side is finished reacting, and has given up all of its extra electrons.

The wires that the electrons travel through are made of metal.  Remember that metals like to give up their electrons.  So when they encounter an electron 'push' from one side of the battery, the electrons march down the wire, replacing the one that has moved in front of it.  Materials that are note metal hold on to their electrons too much to have them get pushed.

Got it?  Just don't stick your fingers in an outlet, and you'll be OK.  More importantly, the fashion report.  SK decided that she needed her Doc McStuffins lab coat today, but we couldn't find it.  We figured it was probably in the wash.  She settled for her Minnie Mouse ears (happily) and the safety glasses.

I got a 6V lantern battery, some aligator clip wires and a small LED bulb.  I spent less than $10 on the setup, but you could dissect an old flashlight, and probably accomplish the same experiment.  I connected the wires to the battery and bulb in a circuit.  We talked about the electrons moving around the path.  SK traced the path with her fingers.  I disconnected the battery "Hey, you turned the light off!"  We traced the path again, and wouldn't you know it...the path was broken.

I also cut one of the wires open, so we could see what was inside.  I asked SK to describe the inside.  It looked like: thread, shiny, and sharp.  I asked what else could be shiny and sharp...she didn't quite pick up what I was putting down.  I grabbed a kitchen knife; both shiny AND sharp.  What is it made out of?  Metal!

To complete the broken path, we needed metal!  She suggested we try the knife.  Light bulb = on.  I suggested a paper clip.  Light bulb = on.  She suggested her magic fairy wand.  Light bulb = off.  We tried to figure out what it was made of...sure wasn't metal!  We tried a glass bottle.  Light bulb = off.  Lastly, we tried her necklace.  Light bulb = on.  That was about all SK had in her.

But wait!  "Daddy, can we do the one with the food coloring and water!  I want hot water because it went SO FAST!"  So we finished the night mixing colors.

Your homework:

  1. Find some things to connect to a battery.  What could we use other than light bulbs?
  2. How did you describe electrons to your SK?
  3. Did anything conduct the electricity that surprised you?

Time to Science!

Sunday, March 2, 2014

Museum of Science and Industry

So the Science Kid and I decided to take a field trip this week to the Museum of Science and Industry in Chicago.  This elder-statesman of the Chicago museum scene consistently maintains its reputation as, not only the best in Chicago, but one of the best in the world.

First we saw the Treasures of the Walt Disney Archives. The SK is also a DK (Disney Kid) so she nearly exploded.  They had props and costumes from the live action movies, some behind the scenes video, and a cartooning class.  The princess dresses alone were worth it for the SK.  Needless to say, she had a blast.  In honor of Disney, we wore our Minnie and Daisy shirt along with a crown.  Don't worry though, we brought Wonder Woman along in our purse.

Now, on to the Science.  Or maybe the Industry.  SK was crazy excited to see the airplane and the trains.  I'm not entirely sure why.  We ignore the few toy cars and planes we have at home.  There are train tracks about that never get touched.  Regardless, we ran upstairs to jump in the plane.  She spent some time air-traffic controlling, serving me drinks while I sat  in the back of the plane, and staring at the cockpit.  She was seriously bummed that we couldn't get in and steer the plane.  We discussed what the different nobs and levers did.  The great part is, I had no idea about most of them!  We got to guess, make comparisons to cars, and make up some silly the pizza oven over the copilot's seat!

The Science of Storms is a big exhibit.  It is definitely skewed toward older kids, and even adults.  We got to look at the huge tornado simulator, and played with some prisms, but the 'lightning ball was the big hit.

We also spent quite a bit of time down on the farm at Farm Tech.  Of all the exhibits, this is probably the least interactive, which really frustrated SK.  We wanted to feed the cows.  Nope, it was pretend.  We wanted to plant some crops.  Nope, just a picture.   At least there were tractors to drive.

Next to Farm Tech is the Idea Factory.  This is similar to many of the Children's Museums in the area.  There were levers and gears and water and balls and air.  The interactivity is great, but there was little 'science' to learn about.  There is a giant balance that started a good conversation of putting the same amount of foam blocks on each side.  As far as the rest, we weren't that in to it, but it was lunch time, so we took a break in the food court.

Energy was definitely low, but we still had to see the baby chicks.  The genetics was FAR beyond SK, which was fine.  We just wanted to see some baby birds.  We got to see a newly hatched check that had JUST emerged from the egg.  It was struggling quite a bit, and we got to talk about how helpless babies are.  They need to be fed, changed, snuggled, repeat.  She was very sad for the chick that its mommy and daddy weren't around.  Of course they were just in the other room and come out when everyone leaves the museum.

As we were walking toward the car (Advanced Beginner Note:  Save $10 on parking if you park on the east side of the museum off of Science Drive.  It is surface parking, and a bit of a walk, but the meter is only $10!), I asked what SK's favorite part was.  She thought about it and said Yesterday's Main Street.  She is fascinated by things that happened before anyone she knows was born.  (We had an uncomfortable encounter with a painting of the Great Chicago Fire at a Potbelly's.  We often talk about the fire.  "Why did that cow kick over a lantern?  Was everyone mad at the cow?")  The Main Street scene has some great old artifacts from pharmacies, doctor's offices and clothing stores.  Of course, my little SK loved the fancy Dresses!

Chicago MSI is a great Saturday outing.  We got there right as they opened at 9:30, and had many of the exhibits to ourselves, even on a Saturday.  It is so big, that there are rarely crowds or long waits to see individual items.  AND there is so much to see!  It also helps that teachers get in for free...

Until next Saturday, Keep Scienceing!

Saturday, February 22, 2014

Particle Diffusion (Water and Food Coloring)

So, I may have overestimated SK's attention this week.  We had a good time, but her questions and observations went to a different place.  But, hey!  This is science, not cooking.

First, the science.

All matter is made of molecules.  These molecules are constantly in motion. The motion is random...that is, the movement of each individual particle is unpredictable.  As we zoom out, the pattern holds.  The phenomenon was first observed in 1827 by Robert Brown.  He observed pollen grains in water.  Today, in his honor, we refer to it as Brownian motion.

As we continue to zoom out, the sum of the speed and direction of these particles (physics and math people call these vectors) equal zero.  This makes sense.  The chair you are sitting on, stays a chair.  Its solid.  Even though its particles are in motion, together they stay relatively still.

That's great, but what does this have to do with food coloring?  I thought we were going to make frosting!  Actually, so did the Science Kid.

Stick with me.  Even though the sum total of the particles motion is zero, if there are different types of particles in a mixture, they will ultimately mix.  This process is diffusion.  Particles move form an area of high concentration to low.  You've experienced this when someone wearing to much cologne walks in a room.  Those closest to the offender begin to cough and snicker.  Over time, the cologne diffuses until everyone in the room can smell it.

We took it a step further.  When temperature increases, so does the speed of these particles.  At some point, the speed becomes so great, the molecules of a solid break apart and become a liquid, and then ultimately a gas (some day we'll get to phase changes, don't worry!).

Lesson over...on to the fashion report.  We got safety glasses for today.  Knowing the SK, I knew what I had to do: PINK!  No magic wand or lab coat, but Doc McStuffins was represented on the T-Shirt.

We started with tap water in a glass.  We put two drops of McCormack's Food Coloring (I tested my fancy organic food coloring gel ahead of time and it took FOREVER to dissolve) into the glass.  Instead of stirring, we watched the drops spread throughout the glass.  We talked about how pieces of water, called molecules, were moving all about. SK was not that into it.  She REALLY wanted to stir, so we stirred.  I pointed out the the pieces of water were moving even faster, and that the pieces of food coloring could mix faster.

Next, we did the same with near boiling water.  I explained that the molecules of the hot water were moving SUPER fast.  We watched the food coloring diffuse quickly.  This actually caught her attention, but first more stirring.

Now, we tried water that had been chilling in the fridge.  "If the food coloring spread quickly in the hot water, what will happen in the cold water?"  "It will go sloooooowwww!"  And, so it did.

I then asked her if we were done, but of course we weren't.  There was one more color, so I asked what type of water we should use.  SK thought about it, and said warm.  Makes sense, we did hot, tap and cold water, so warm was next.  Turns out she just wanted to stir more.

Today's lesson may have been more for me, then for SK; go where the questions take you.

So, your homework:

  1. Was your SK into it?
  2. Did you try anything other than different temperatures of water?
  3. You could even try measuring the temperature of the water or measuring the seconds it takes for the the food coloring to diffuse.
There you go...Time to Science!

Saturday, February 15, 2014

Acetic Acid and Sodium Bicarbonate (AKA Vinegar and Baking Soda)

For our inaugural Saturday, we went with the old stand-by: Vinegar and Baking Soda.  Really?  The Bobby Brady volcano?  Yup!  That's the one.

First, the science.

Solid Baking Soda (Sodium bicarbonate:  NaHCO3) and aqueous (or dissovled in water) Vinegar (Aceitc acid: CH3COOH) react to become liquid Water (H2O), gaseous Carbon dioxide (CO2) and Sodium acetate (C2H3NaO2).  If you want to get all chemistry about it:
NaHCO3(s) + CH3COOH (aq) à H2O(l) + CO­2(g) + C2H­3NaO2(aq)

The reactants, or ingredients, are commonly found in any kitchen.  Vinegar is usually about 5% (by volume) Acetic acid.  The other 95% is water.  Sodium bicarbonate is a solid, which is not mixed with anything, traditionally (except in Baking Powder...don't use Baking Powder!).

The reaction is slightly exothermic, meaning that it releases a small amount of heat.  The product, Carbon dioxide, is released as gas, and is seen as bubbles rising to the surface.  The product, Sodium acetate, is soluble, meaning it dissolves in water.

There are a few pieces of evidence that a reaction can produce:
  1. Color Change
  2. Temperature Change
  3. Bubbles
  4. Appearance or disappearance of a solid (called a precipitate).  This can sometimes be seen as cloudiness in the solution.
In this reaction, our primary evidence is the gas release, causing bubbles.  The temperature change is slight and the Sodium acetate can't be seen because its dissolved.

Are you sweating yet?  Don't worry.  That's the end of the Chemistry lesson.

When I told the Science Kid that it was time to do an experiment, she ran upstairs to put on her Minnie Mouse dress and to grab a magic wand.  Seems logically enough.

I asked her what she thought would happen when I mixed the two together.  She held up her hands and said "I don't know!"  And why should she?  So we mixed 1/8 cup of vinegar and 1 teaspoon of baking soda (we'll get to the metric system later....don't worry!).  Bubbles.  "Whoa!"

Next, we kept with the same amount of vinegar, but measured out two teaspoons.  BEFORE, she dumped it in, I made the SK predict what she thought would happen.  "More Bubbles!" and again in another glass with three teaspoons.

We used the same type of glass each time, so we could see how far up the bubbles reached.  We marked the highest spot with a dry erase marker.  This way, we could compare after the reaction was finished.

SK made an observation that there was still 'white stuff' at the bottom of the glasses.  How do we get rid of it?  More vinegar!  Now we abandoned measuring, and just had some fun.

Eventually, there stopped being so many bubbles.  Why?  SK once again threw up here hands "I don't know!".  We looked at the bottom of the glass and noticed that the baking soda was almost gone.  In science talk, the reactant was depleted.

We then turned our attention to one of the other glasses.  Even though we left it alone, there were still bubbles emerging slowly from the baking soda at the bottom of the glass.  When the vinegar was in low concentration, the reaction still took place, but very slowly.

First Science Saturday in the bag.  Bath time!  While we are splashing with bubbles, I get the question "What happens if we mix the baking soda with water?".  Apparently SK is a better scientist than her dad, because SHE remembered that we needed a control group!  SK made a prediction, we tried it out.  Nothing.  Because, as we discussed you need both reactants to make the reaction happen.  SK waved her magic wand, and thus concluded our first Science Saturday!

Now its your turn!
  1. What did you try?
  2. Did your SK surprise you?
  3. What was your SK's outfit of choice?

Saturday, February 8, 2014

Welcome to Science Saturday!

The Science Kid
Hi there!  Welcome to Science Saturday.  Every week (or as often as Science Kid allows) I'll bring you a scientific investigation that can be done at home with common (or easily obtained) materials.  Nothing will be ground breaking.  You've probably done all of these yourself at some point.  We aren't going to write your doctoral dissertation or win a Nobel Prize with these investigations, but we will work your Science Kids through some basic scientific processing.

What kinds of things will we be investigating?

Biology, Chemistry, Physics, Geology, name it!  We are surrounded by all of these sciences every day.  Kids are naturally curious about the world around us, so we'll try to work through some things that the SKs are thinking about anyway.

Are we just going to do cool stuff?  Is that science?

Hardly!  Science has nothing to do with the reaction, the dissection or the equipment.  Science has everything to do with the questioning.  We'll talk through some basic questioning techniques.  We'll try to get the SKs to ask their own questions.  We'll make predictions and even get through some basic math analysis.

Why should we listen to you?  Are you Mr. Wizard or something?

I wish!  He was my favorite...along with the great Carl Sagan.  Like I said, the science isn't going to be revolutionary.  The two things that I have going for me are that I have taught all levels and types of High School science for over a decade and I have an SK that asks a TON of questions.

Why do you keep saying 'we'?

Science is collaborative.  Science is cooperative.  The days of the old guy locking himself in a laboratory making an earth-shattering discovery are over.  Today, the best science happens when teams work together, share ideas and question each other.  Most discoveries are not only done with multiple people, but they often span multiple disciplines, multiple universities, multiple countries, and even multiple languages!

Science Saturday will work best as a partnership.  Tell us how it went.  What kinds of questions did your SK ask?  Did you change the investigation?  What worked?  What didn't?  The more interactive we make the investigations, the better an experience we can make for our SKs.

If you are interested in following along with Science Saturday, be sure to subscribe to the blog, like it on Facebook and let other parents know!