Thursday, September 30, 2010

Total Cereal: Iron Fortified

This activity can be used for several different curriculum areas: elements, magnetism and nutrition

Back in the day, Total cereal used to run a series of commercials in which a person had to eat a large number of bowls of their favorite cereal in order to get the same amount of vitamins and minerals they could get in one bowl of Total.  One of those nutrients is iron.  Check out how they fortify their cereal....

Pour some cereal into a cup or bowl.  Pour some water on the cereal and let it sit for 15-20 minutes; enough for it to get nice and soggy and too gross to eat.

Place a magnet (use the strongest magnet you can get your hands on - a regular magnet works, but the stronger the magnet, the better the results) in a plastic baggie*.  Then, use the magnet to stir up the cereal sludge.

When you pull out the magnet, you will find that you have small pieces of iron sticking to the magnet!  The cereal is fortified with iron filings!  Perhaps not the most usable form of iron for your body, but iron none-the-less.
*Putting the magnet in a plastic baggie serves 2 purposes:
 1 - It makes clean-up a LOT easier!
 2 - It can be hard to see the iron pieces on the magnet, but if you pull the baggie off and place it on a piece of white paper, the iron will be easy to spot!

Wednesday, September 29, 2010

Is It Living: The Martian and the Car

Images from 

There's a fun living/non-living scenario at Biology Corner

A quick synopsis:
A martian is sent to Earth to find evidence of life.  He brings back a car.  He's now on trial for not carrying out his duties. 

Have your students take on the roles of Defense Attorney and Prosecuter. 

I worked with a social studies teacher who was very interested in debate and mock trials.  She was always game for teaming up to turn this simple activity into something a little more involved and meaningful for the students.  Maybe you work with someone of a similar personality!

Tuesday, September 28, 2010

Earth vs. moon: Diameter Comparison

Draw a 40 cm (diameter) circle on your board.  [You could also cut out a 40 cm circle, but that takes a bit more work - you need to use a piece of poster board or tape several pieces of paper together].

Tell your students that that circle is the Earth (you could get creative and add some continents and oceans to your circle drawing to make it more convincing, if you're so inclined).  They now need to cut out a circle to represent the size of the moon.

Have the students tape their moons on the board around the Earth drawing.  Are the moons about the same size, or was there a lot of variation in the students' guesses?

The correct size for the moon is approximately 10 cm.  Measure the students' moons and remove all but the one closest to accurate (if there are none that are terribly close, you might want to remove them all and replace them with one of your own that's correct).

After comparing the size of  the Earth and moon next to each other, move the moon 1200 cm (12 m) away from the Earth - that's the distance between the two to the same scale.  Quite something, isn't it?

Presented by Dr. Christine Anne Royce (Shippensburg University) at the 2007 New Jersey Science Convention.

Monday, September 27, 2010

Inference Folders

One of the skills students need to develop as they learn to think like scientists is inferring. 

This is a simple activity to assemble, and is a good way to reuse old manilla folders and calendars.

Place a calendar picture inside a manilla folder; attach it with a piece of two of tape or a quick swipe of a glue stick.  Then, cut several small windows into the folder at various locations (cut on three sides, so you're left with a flap that can be opened and closed).  Number the windows in the order you'd like the students to open them.  Seal the edges of the folder with tape or glue. 

When students get a folder, they open the first window and observe what's inside.  Based on what they see, they need to infer what's inside.  They will then open the second window and add that information to what they previously gathered and refine their inference.  They will continue in the same manner until they've opened all the windows. 

At this point, your students will want to open the folder.  But, most of the time, scientists can't just "open the folder" - if they could, they wouldn't need to infer.  Scientists have to work with the information they have.  The best they can do is find ways to gather more information. 

Friday, September 24, 2010

Book: A Really Short History of Nearly Everything

I've previously espoused my love for Bill Bryson's A Short History of Nearly Everything.  This, A Really Short History of Nearly Everything, is the kid-friendly version of that book. 

This version uses text from the original (which I really like about it) and it adds lots of illustrations, many of them humorous, which fits right in with Bryson's writing style.  Of course the text is abridged to student-friendly length and content.  Each topic is given a two page spread, and like the original, you can open the book to any page you wish and dive right in. 

I think I would stick with the original for reading aloud to students, as the text flows better and provides more information  than in the Really Short version.  The text in A Really Short History of Nearly Everything is fragmented and interspersed amongst the pictures, which makes it difficult to read aloud (unless you're looking to share a single fact), but it's wonderful for students to pick up and page through on their own.

Thursday, September 23, 2010

Light: Seeing Color

[The nature of this activity makes it difficult to photograph (at least for one with limited skills in that area, such as myself).  Try it yourself for the best results.]

A little refresher on color and light...
--White light is composed of all the colors in the spectrum (red, orange, yelllow, green, blue, indigo, violet).

--An object appears red because it reflects the red light and absorbs all the other colors.
--An object appears white because it reflects all the colors in the spectrum, and absorbs none. 
--An object appears black because it absorbs all the colors in the spectrum, and reflects none. 

What you'll need...
--a red toy car
--a blue (or other non-red color) toy car
--a red light (this could be a laser pointer - be careful!, a filtered flashlight, a toy - mine came from a cereal box)

You'll need to do this demonstration in a darkened room.  If you can't get your room dark enough, you can set it up inside a large cardboard box - but only a few people will be able to view it at a time.

To perform the demonstration...
Before darkening the room, show the students the two cars, so they can see that one appears red and the other blue.

Turn off the lights.  Shine the red light on the red car.

The car will still appear red because it is reflecting the red light (it's not absorbing anything since you didn't shine any of the other spectrum colors on it, but that doesn't change what you see).

Now shine the red light on the blue car.

The car will appear black (or at least a dark shade - to get black you'd need a totally dark room and a pure red light).

Here's why... 
Your light is only emitting red light.  The blue car only reflects blue light.  There is no blue light for the car to reflect.  The red light is being absorbed by the car.  The result, for our eyes, is black, or the absence of color.

Wednesday, September 22, 2010

Chromatography: Spinach

Is spinach colored by purely chlorophyll (green pigment)? Or are there other pigments hiding in there, masked by the presence of chlorophyll?

Before beginning, if you aren't familiar with chromatography, you may want to review the basics, here.  

Use a quarter to rub spinach into a piece of filter paper, a couple of centimeters from the end of the paper. (If you’re doing this at home and don’t have lab grade filter paper, have no worries! A coffee filter works beautifully (that’s actually what I used with my students – why spend the money on expensive filter paper!) and even paper towels can be made to work).

 Put about a centimeter or so of rubbing alcohol in a cup.  Place the filter paper in the cup, so the end is in the alcohol, but the spinach transfer is above the liquid.  Allow it to sit.

Now, here's where it would be nice to have a picture of the finished chromatograph.  But, milk spilled on mine before I snapped a picture and I haven't had the opportunity (or spinach) to recreate it.  It's subtle, but you can find both green and yellow pigments on the paper, if you look carefully. 

Presented at the 2003 New Jersey Science Convention.

Tuesday, September 21, 2010

Crystal Models

Minerals are made of a crystalline structure.  Many students don't really know what that means.  And a verbal explanation won't suffice for many middle school students.

Have the students make models of the basic crystal shapes using these paper models (or if you don't have the class time to devote to this, you could make a set to have on hand when it comes time to explain crystalline structure*):

Cubic Crystal
Tetragonal Crystal
Hexagonal Crystal
Orthorhombic Crystal
Rhombohedral Crystal
Monoclinic Crystal
Triclinic Crystal

*If you're making a set for classroom use, to have on hand year after year, you might want to go to the extra effort of making your models with cardstock.  They take a little more effort to fold, but they'll hold up better.  Also, make sure you label your models with the crystal shapes - you may be able to remember them for a couple of days, but when you pull them out next year... :)

Monday, September 20, 2010

Air Pressure and Bernoulli: Balloons!

Hang two balloons so they are a few inches from one another.

Blow through the gap in the middle of the balloons.

The balloons move together!  You pushed the air molecules from the middle out of the way, allowing the air on the other side of the balloons to push them toward the middle.

Friday, September 17, 2010

Website/Book: Invitations to Inquiry

 I have found what looks to be the ultimate treasure trove of science demonstrations and activities for elementary and middle school students. 

Tik Liem published a book called Invitations to Science Inquiry.  It's downright difficult to find a copy of this book today, and if you can, it'll cost you plenty.  But, ERIC* has the complete second edition available for free.  That's 400 discrepant events** for you and your students, for FREE!!!  And they cover every branch of science. 

In the abstract, Liem writes:
In the teaching of a science concept, it is important for the teacher to arouse the student's curiosity.  Once curiosity is aroused, the students will learn much more on their own than the teacher can ever teach them.  The use of discrepant events in the teaching science is one of the best methods to arouse this curiosity.  This book is a collection of thoroughly tested discrepant events.  They can be used to initiate or sustain a lesson in virtually any topic of science at the upper elementary or intermediate level.  They can be used as reinforcement activities or as challenging problems for further inquiry. 

Seriously... I think I've been channeling Tik Liem for the past 8 years without even knowing of his existence.  I've been trying to learn a bit more about him and his experiences, but have yet to come up with anything beyond this publication.  

In the meantime, I'm figuring out how I want to print this massive document because I think I need to have it in hard copy - there are just too many high quality demonstrations I need to try out.

I"m familiar with several of the discrepant events in this book (and you are too, if you've been reading my blog), and they are demonstrations that easy to set-up and come through for me every time.  I'm looking forward to finding more of these as I work my way through the book.  And I thought I might run out of material for this blog... I'm good for a while now!  (Although I won't be doing much of anything in his chemistry section, as they all require chemicals and safety equipment that I just don't have at home).

Do yourself a favor and go check out Invitations to Science Inquiry NOW!  

*ERIC is the Education Resources Information Center run by the US Department of Education - a very legitimate site.  My past experience with it came in grad school - it has lots of journal articles and research papers.  I still think that's the majority of the content, but after learning of Invitations to Inquiry, I might have to explore a bit more and see if there are other treasures lurking about.

**Discrepant events are things that counter-intuitive.  You need to look closer at the science involved to understand what's happening.

Thursday, September 16, 2010

Chromatography: Pinwheel T-Shirt

Sharpie markers may not be soluble in water, but they are soluble in rubbing alcohol.  Use this property to your benefit to create some wearable art (and science)!
Place a dish pan or plastic shoe box inside a plain white shirt.  Pull the shirt taut and rubberband it in place.

Use the markers to make a ring of dots where you want the pinwheel to appear.

Using a dropper, drop rubbing alcohol into the middle of the ring. 

The alcohol will move outward, through capillary action, and carry the ink with it.

If the ink is made of a mixture of colors, you will see the colors separate.  If it's made from a pure color, you will simply see the color radiate outward.

Move the shirt on the box and make another pinwheel. 

Get creative...
...try making your ring of dots with a variety of colors
...what happens if you make your dots in a shape other than a circle?
...what if you start with one central dot?

Wednesday, September 15, 2010

Milk Fireworks

Pour enough milk into a pie plate to cover the bottom.

After the milk has stopped moving, place drops of different colors of food coloring in the milk.

Dip a toothpick in dish soap and then touch it to the middle of the milk.

The food coloring mixes with the water in the milk.  The soap is attracted to both the fat and the water in the milk.  When you add it to the milk, it immediately begins to grab those parts, which results in a lot of mixing and movement, which, thanks to the food coloring, you can see. 

The soap also breaks the water's surface tension, allowing all kinds of movement to occur.
 These pictures were taken using 1% milk - try it using whole milk, with more fat molecules for the soap to grab onto and see what happens. 

Tuesday, September 14, 2010

Why is the Sky Blue?

Fill a glass with water, then add a few drops of milk so it becomes a little cloudy.

Darken the room and shine a flashlight through the milky water.

Look into the glass from above.
The picture exaggerates the color a bit - it looks blue, but not neon blue!

The Earth's atmosphere is filled with dust and water drops.  These particles bend the light from the sun, causing it to appear blue.  In this demonstration, the milk provided the particles to bend the light from the flashlight.

At sunset, the angle of refraction changes and you're able to see colors from the other end of the spectrum - reds and oranges.

And, if you've ever watched a sunset in a region where there have been forest fires, you'll notice even more intense colors - more particles (smoke from the fire), causing more refraction. 

Monday, September 13, 2010

Survey of the Science Textbook

Earth Science (Holt Science and Technology)
This is the book for which the survey below was written.

Here’s one way to introduce your students to their new textbook and familiarize them with some of its features.

It’s also something that students can work on while you’re doing some of the other beginning of the year paperwork.

This is obviously something that would need to be personalized to your textbook, but I’ve provided my version to give you some ideas of where you can take the activity.

1. The TITLE of your textbook is _____

2. The text is written by (choose one)
a. one AUTHOR
b. more than one AUTHOR

3. Look at the TITLE PAGE of the text
a. What is the COPYRIGHT DATE of the book? ______
b. What does that mean to you as a student studying science?

4. Does your text have a TABLE OF CONTENTS?

5. Does your text have a GLOSSARY?

6. Does your text have an INDEX?

Using the TABLE OF CONTENTS, write the name of these chapters:

7. Chapter 1: _____
8. Chapter 3: _____
9. Chapter 7: _____
10. Chapter 8: _____
11. Chapter 9: _____
12. Chapter 11: _____
13. Chapter 13: _____
14. Chapter 15: _____
15. Chapter 16: _____

Fill in the following chart. Put “yes” in the GLOSSARY column if the word is found in the glossary. Put “yes” in the INDEX column if the word is found in the index.

16. Anemometer
17. Batholiths
18. Hypothesis
19. Meter
20. Metric
21. Petrifacation
22. Scientific Method
23. Seismology
24. Troposphere

25. Notice that each chapter has two yellow pages. The headings of the yellow pages are:
a. _____
b. _____

26. What color is the APPENDIX in your textbook? _____
After looking through the APPENDIX, name at least one thing you might use it for. __________

27. Find the LAB BOOK in the back of your textbook. What color are those pages? _______
Take some time to look through the LAB BOOK. Name at least one experiment found in the lab book that you would really like to try this year.

Friday, September 10, 2010

How Does That Work: Doing the Back Float

This is a simple activity, but its explanatin is a bit sophisticated.  Therefore it's a good candidate for older and/or more advanced students.  But, don't let that stop you from trying it with younger students - keep your explanations basic and you might be surprised at what they take away from it.

What you'll need:
Baby oil
Water bottle
Index card
Sharpened pencil
Hole punch

What to do:
Prepare a bottle, filled about half way with water and the remaining way with baby oil. 

On one side of an index card, color with a pencil, getting as much graphite as you can onto the index card.

Use a hole punch to punch the index card.

Place the hole punches into the bottle of oil and water.

What you'll see:
The dark side of the holes will always face the oil and not the water.  You can shake it up and they'll always return to that position.

Graphite is a good conductor, which gives it a negative polarity.  Water also has polarity, and it repels the graphite, so the graphite side will face the oil.

You can also talk about things like density, immiscibility and the like with this activity.

How Does That Work is a series of products and demonstrations that you can present to your students and challenge them to explain the science of how they work. Make sure you decide ahead of time what you'll accept as a valid explanation - can it be printed straight off the internet, written in the student's own words, or does the student need to be able to explain it to you conversationally? What will a valid explanation earn the student - a prize, extra credit, a feeling of goodness?

Thursday, September 9, 2010

Electricity: Christmas Light Circuits

Have your students build simple circuits out of easy-to-find, inexpensive materials. 

You'll need a strand of Christmas lights* and D batteries.

To prepare the lights, cut them apart into 2 or 3 light chunks.  You'll want to invest in a cheap (or higher quality if you desire, but for this, cheap works!) wire cutter/stripper for this.  The wires are thin and could probably be cut through with a scissors, but you'll want the tool for the next step...

Strip about an inch of the insulation from each end of the lights. 

In class, hand each student (or pair of students) a strand of lights and a battery.  Have them figure out how to make the lights light.  That's pretty easy....

Then give them a second strand of lights and have them figure out how to get both strands to light.  There are two different ways to accomplish this...

1 - Twist the ends of the strands together to make one large loop.

2 - Hold the ends of each strand to the battery, so you have two loops.

Once students have found one way to light both strands, challenge them to find a second way.  After students have had the chance to experiment, talk with them about parallel and series circuits - they'll understand it, after having created them on their own!

In my experience, this leads to all kinds of extensions....
As you add strands, the lights will become dimmer.  Why?  What can you do to make them brighter again? 

The students will want to see if they can string all of their lights together and see if they can light - let them try!  How many batteries will it take?

Are smaller batteries strong enough to power the lights?

*You'll want to use clear bulbs.  One time I found a string of blue lights in the garage, which I thought would be perfect for this, seeing as I didn't want them for anything else.  But, since you're only using a D cell, the light is too hard to see through the colored bulb.