Archives for November 2009

Elephant toothpaste on the David Letterman show – by Rajeev Goel

The following wonderfully fun post is shared by Rajeev Goel, the creator of Our Science Fair which I referenced in yesterday’s post about organizing a science fair.

A couple of weeks ago — Nov. 12 to be exact — David Letterman had Kid Scientists on his Late Show. This is something he does once every few months, and in this case, the Kid Scientists were his first guest on the show, coming on even before his A-list movie star, Amanda Peet. I applaud The Late Show for doing this, and I just think it’s an amazing idea. I love the fact that ordinary school kids are getting their chance at five minutes of fame. In a world where science isn’t considered the most glamorous of professions, these kids are basically selling scientific exploration as being fun, cool, and something to aspire to. It’s also noteworthy that the kids chosen to be on the program are diverse in terms of gender and race. On Nov. 12, he had a boy and two girls, one of whom was Asian Indian.

Many would agree that the first girl, “Heather”, had the most exciting demonstration. The video of her demo is here:

For the curious among you, I thought I would break down her demonstration.  It can be tough to follow everything she says on air, since things move along fairly quickly.
First, she says that she has two beakers of cyalume.  Cyalume is another name for the chemical “diphenal oxalate”.  But really only the red beaker contains cyalume, and in fact, it’s a mixture of cyalume and a special fluorescent dye.  The chemical formula for cyalume is:
The other beaker, the one with the clear liquid, contains a hydrogen peroxide solution:
12-year old Heather says that when you “mix the two together, they will undergo chemiluminescence.”  She proudly and patiently explains to Mr. Letterman that “chemiluminescence is when the chemicals will give off cool light due to the excitations in the electrons.”  The chemical reaction that takes place is as follows (from Wikipedia):
Wikipedia explains further:
By mixing the peroxide with the phenyl oxalate ester (aka, diphenal oxalate), a chemical reaction takes place; the ester is oxidized, yielding two molecules of phenol and one molecule of peroxyacid ester (1,2-dioxetanedione). The peroxyacid decomposes spontaneously to carbon dioxide, releasing energy that excites the dye, which then relaxes by releasing a photon. The wavelength of the photon—the color of the emitted light—depends on the structure of the dye.

Once they have their bright yellow glowing liquid, Heather asks Mr. Letterman to pour it into the giant graduated cylinder, which appears to already contain about half a liter of liquid dishwashing soap.  Then, she asks him to add the manganese dioxide:

Since manganese dioxide is actually a black powder, I can only assume that the black liquid in the measuring cup is actually a water-based manganese dioxide solution.  When Mr. Letterman adds this to the giant cylinder, the crowd goes wild.  As Heather explains, “The manganese dioxide will act as a catalyst and break down the hydrogen peroxide into water and oxygen gas.  The oxygen gas bubbles will get caught in the soap, and it will also get very hot.”  The chemical reaction is as follows:

As you can see, the manganese dioxide is not actually part of the equation.  That’s because it’s only a catalyst, and doesn’t actually get consumed as part of the chemical reaction.  Anyway, resulting the water and oxygen gas (and heat) all get mixed up in the dishwashing soap causing it to create enormous amounts of suds, enough to overflow the giant graduated cylinder.

Sometimes this demonstration is known as “elephant toothpaste” (for obvious reasons), and you can find numerous examples on the web of this experiment being performed by kids in their school chemistry labs.  For example, check out this video.

Well, I hope that helps clear things up, and now you know enough to try this out yourself, assuming you can get a hold of the chemicals.  If you do, please follow all appropriate safety precautions … these chemicals are dangerous, and the chemical reactions produce a lot of heat.
Please leave a comment if you enjoyed this post.  Teachers and science fair coordinators:  don’t forget to get your free science fair website at
Rajeev Goel

Introducing – Our Science Fair

boardIf you’ve ever been involved in the organization of a science fair, you know what a hassle it can be. Getting paperwork home to parents is the first hurdle. Getting it back is never easy. But entering registration information into a database is an overwhelming task for someone.

Rajeev Goel learned all of this last year when he volunteered to help put together his daughter’s science fair. A programmer for IBM, he knew that there was a better way. He came up with a web based registration system that eliminated most of the science fair paperwork. After his school used the system successfully, he made it available to any school – including yours at a terrific site called Our Science Fair. And unbelievably, it is FREE.

When you check out Our Science Fair, you’ll also notice some other great advantages. You can customize it to your school site. Parents can upload their science fair pictures. Organizers can send emails to registered students. And you can buy science fair supplies with proceeds going to your school.

Check out all of this and more at Our Science Fair.


P.S. Whether you’re an organizer or a participant in your science fair, you can get a free science project guide for your students – or yourself – at 24 Hour Science Projects!

Cosmetology Science Experiment

Earlier this week I talked about our new science project about hair. I suppose, since we are scientists, that I need to call it a Cosmetology Science Experiment. Anyhow – getting this project just right has been about as difficult as getting the right hair cut for my boys. But it’s been fun! And we’ve learned all sorts of things along the way.Cosmetology Science Experiment

For example, we had a heck of a time getting the hair the exact length we needed it. I mean, hair is little, tiny, and hard to grasp. We figured out a way – quite by accident – to get each strand the perfect length. Our other discovery is finding out what sort of stuff is in cosmetology products. We have boys, and they don’t exactly use anything on their hair other than shampoo – and sometimes I have to remind them to use that! Anyhow, I didn’t know about peroxide and lemon juice and the difference between highlighting and stripping color. Thanks to some interviews with real cosmetologists, I’m much better informed.

Of course, we have more fun middle school projects up our sleeve. Right now my kitchen has a slight smell of sour milk and our cabinets are splattered with purple cabbage juice. I’ve got orange pulp in my fingernails, and the taste of club soda in my mouth. (I know, you’re not supposed to taste any of the experiments!)

But we’re sailing toward getting this package of products done! I can’t wait.

P.S. If you need a science project now, get our free Parent’s Guide to a Science Project at 24 Hour Science!

Science Project About Hair – Our Hair Raising Fun…

hair science projectOur house has turned into a laboratory of sorts; we’re getting the new Middle School Science Projects ready to roll. You can see some of the things we’re using to the right.

One of the things we’re working on today is our new science project about hair. In the experiment, we’re measuring the strength of hair after it’s been treated with various types of hair products. To do this, we had to find a way to hang strands of hair. The first attempt was to simply tie a knot. That was NOT easy, and after I tried for fifteen minutes, we decided it was too impractical to think that a middle schooler would be able to do it.

So then we thought about tape. First, I used medical tape, because it’s white and you can write on it – important to keep up with the variables. But the medical tape didn’t hold the hair; it just slipped out. Regular cellophane tape wasn’t successful either. I almost gave up, but we finally found a great solution. You’ll have to get the middle school guide to find out!

Experimenting before the science experiment is an important part of our science. We’ll have all the kinks worked out of the hair project (pun intended!) when it is published. Our goal is to take the guesswork out for families, so that they have a step by step list for a cool science project that works!


P.S. We’re kicking around titles for our science project about hair – “Hair Today, Gone Tomorrow”, “Splitting Hairs”, “Hair Conditioning”, and other less catchy attempts. Leave a comment below if you have any ideas.

Middle School Science Projects

Science Projects were easier in elementary school. Back then, you could submit a model rocket, an egg sucked into a bottle, or a simple science report on electricity. It’s different in middle school. Middle School science teachers want creative ideas, specific elements, in depth research, and detailed logs of the whole science fair process.

Finding a middle school science project that meets all these criteria has always been a challenge for our family. Our teachers wanted an experiment based, investigative project for the science fair. There are five different types of science projects, but most of the books in the library had projects that were actually demonstrations or models. It’s very important that you read the directions from your teacher and/or the science fair, and make sure that the project your child chooses fits into the right category – especially in middle school.

Here are the five types of projects.

1. Investigative projects – Most science fairs require students to submit an investigative science project. This type of project has an experiment that tests an hypothesis. The experiment will follow the scientific method, and may require a control group. (If you’re unfamiliar with this vocabulary, check out the free resource below!)

An example of an investigative project would be “How does salt affect the boiling point of water?” This can easily be tested by our experiment which adds different amounts of salt to water and recording the temperature at which it boils.

If you see the words experiment, scientific method, control and/or variable on the project instructions, you’ll probably need an investigative project. As mentioned before, they’re not easy to find. (Hint: We’ve got a whole pack of investigative projects at 24 Hour Science Projects…)

2. Demonstration projects – In this type of project a student demonstrate a scientific principle, and lots of time the teacher wants it presented in front of the class as an oral report. There is no true experiment performed, because there won’t be a control or different variables. (Another hint: We’ve got five demonstration project guides in our “Watch This!” Science Project guides.

3. Research project – Basically this is a science report. Students research a topic, and write what they discovered. Any type of science topic can be used for a research project.

4. Models – For a model project, models are built to explain a scientific principle or structure.

5. Collections – In this type of project a collection of objects is displayed to give an overview of a topic. An example would be a rock collection or a display showing pictures of various animals in a specific family.

Every middle school science fair will have slightly different criteria for projects. As you search for a project, make sure it’s the type of project your school requires. If you need help, check out “The Non-Scientist Parent’s Guide to Science Fair Projects“, which has guides for all the different types of science projects – including the experiment based ones! There is a vocabulary list that gives simple definitions to those vocabulary words you learned in middle school, but promptly forgot.

Believe it or not, science projects are designed to help students learn about science. Figure out which type of project your school requires, and you’ll be one step closer to showing your child how much fun science can be!

Find all sorts of science projects with our excellent guides, including 24 Hour Science Projects, five experiment based projects. We also have five Watch This! demonstration projects, which are designed to be presented in front of a class. Our project guides are perfect for a middle school science project!

Science Project Topics

science fair topics for middle school

Watch for whole new set of science project with science fair topics that are perfect for middle school! In fact, the projects are called Middle School Science Projects. There will be some cool experiments, and one demonstration. Here are the topics that are planned:

1. How do different hair products affect the strength of hair. Girls are especially interested in doing a science project about hair. In this project, you will treat hair, then test its strength.

2. Does the amount of Vitamin C in Orange juice change over time? This is a slightly more advanced version of the popular Vitamin ‘C’itrus’ project.

3. What liquid is best for growing beans. This experiment involves pH and hydroponics, and you get to make your own litmus paper.

4. What makes yeast grow best? This is a project with yeast as the science fair topic, but its a demonstration.

5. This one is a demonstration/model. We’ll be building a solar heater with cans and a window frame.

PS You don’t have to wait for the new package. Get a free science project guide here.

Kids Science Experiments

kids science experiment mouseBecause we’re getting ready to roll out our new package of middle school science projects, I’ve been looking all over for good kids’ science experiments. Trust me, true experiments are not easy to find! It amazes me that reputable science publications will label any sort of science activity as an experiment. An experiment is a test of the relationship between two variables that have measurable results that can be replicated.

Here are some things I’ve found that are great science fair topics, but simply are not science experiments:

~ Making a Potato Canon – This is a fun activity, and it demonstrates how cool science can be, but it doesn’t tst anything. How can you turn it into an experiment? Vary the trajectory, and ask, “At which angle will a potato canon launch a potato the farthest?”

~ What happens when seeds germinate?” – This is listed as an experiment on a teachers’ forum. Can’t believe it. It’s a great lesson, but what are kids comparing here?! Turn it into an experiment by testing “At which temperature do seeds germinate the best?”

~ How do bones change when soaked in vinegar? – This is close to an experiment, but the project I saw didn’t have a way to measure the change. The results of a true experiment must be measurable. If your kids come up with a weigh to measure the amount of weight the bones can support before breaking – you may just have a winning kids science experiment.

That gives me a great idea for another science project experiment, actually…Stay tuned!


P.S. ALL of the projects at 24 Hour Science Projects are experiment based – Hypothesis, Variables, Measurable Results and all!

Toilet Paper Science Project

toilet paper science project

With today’s increased awareness of how important it is to take care of the environment, it’s great when kids can do a science experiment with results that could change the way their own family takes care of the earth. Our toilet paper experiment (or – as the supermarket calls it – “bathroom tissue”), does just that! A Straight Flush helps kids find out which toilet tissue is the most biodegradable. The results of the experiment may influence what brand of toilet paper that home purchases.

A Straight Flush compares the weight of tissue samples before and after spending time in our ‘simulated’ toilet. It requires really accurate scales, which can be expensive. We’re cheap at our house, so we opted to use the scales in the post office. (You could also ask to use the scales at a pharmacy or at a grocery store.) We still laugh at the thought of how it looked for us to traipse into the post office with samples of toilet paper.

Whatever it takes for our kids!


P.S. Toilet Tissue science projects are just gross enough to be great Middle School Science Projects!

Go here to read more about toilet paper and septic systems.