Chemistry Demonstrations and Fourth-graders: A Volatile Mixture?

Last week, I attended the regional meeting of the National Science Teachers Association held here in Minneapolis. I enjoyed seeing so many enthusiastic science teachers attending the sessions and wandering around the exhibit hall.

But when did schools start hiring such young teachers? Nearly all of them were quite a bit younger than me. And I’m not that old!   I’m only … well, let’s just say that I’m a seasoned professional.

Instead of feeling old when I left the meeting, however, I felt young and inspired. I particularly enjoyed watching some of the chemistry demonstrations that presenters were teaching to the teachers. As we participated in these hands-on activities, I could sense the energy and excitement rising in the room. It was the same feeling I get when I put on chemistry shows in my children’s classrooms.

I even started thinking back to the first chemistry show I ever witnessed, when I was a fourth-grader at Meeker Elementary School in Ames, Iowa.

Several years ago I wrote up my memories of that chemistry show, and here’s a copy of that brief essay:

The magic of chemistry first reveals itself to me in 1965, during Spring Break of my fourth-grade year, when my family goes on vacation to the big city of Chicago. The highlight of the trip is the visit to the Museum of Science and Industry. As we amble through the museum, we learn about coal mines and submarines. We see a plastic human heart pumping red and blue fluid throughout a life-size model of a human body. We find out about all kinds of machines, from levers and pulleys to the internal combustion engine. And at 2:00 pm, we gather on bleachers in an open area near the lobby to watch a demonstration of “The Wonderful World of Chemistry.”

I’m seated in the front row. Facing us, on a little stage, is a long table covered with glass bottles of various shapes, sizes, and colors. Placed at one end of the table are a banana, a wooden board, and a pink rubber ball. The ball is exactly the same kind as one I use to play “bounce and catch” at home on my front porch.

The noisy crowd of parents and children quiets down as a man in a white coat steps behind the table and faces us. A red rose is pinned to his lapel. A bright blue balloon rises above him, held in his right hand. He’s wearing glasses that have little plastic shields on the side. This man sure has my attention.

He starts the show by pouring two colorless liquids together, turning them first pink and then purple as he says some magic words. As he mixes other liquids and solids, he creates smoke and fog, makes a volcano overflow, and sets off a loud explosion.

Finally, he tells us that it’s time for the grand finale. He still hasn’t touched the banana or ball. I wonder what he’s going to do with them; maybe he’ll give them out as prizes to kids in the audience. I could always use another pink bouncy ball.

He reaches below the table and pulls out a big metal container with a lid on it. He puts on heavy white gloves and uses a long set of tongs to lift the lid off the container. Fog rises from it. Using a metal scoop shaped like the ladle my Mom uses to serve punch at Christmas time, he scoops up some liquid from the container. We can all see that it’s colorless and bubbling. Suddenly he bends over and pours it on the concrete floor right in front of the audience. I can hear it splatter on the floor. I pull back away from it, just like everyone around me. We don’t want to get splashed with this mysterious bubbling liquid. But as soon as it hits the floor, it disappears. It’s gone. None of us got wet, but I did feel a puff of cool air.

The man in the white coat tells us that this liquid is called “liquid nitrogen,” and it’s colder than the coldest Chicago winter. Grabbing the blue balloon, he holds it down on the table and pours a scoop of liquid nitrogen over it. The balloon shrivels up like a huge raisin, making a crinkly sound as it shrinks. The man lets go of it, and it just lies there. But then, right in front of our eyes, it starts to grow, take shape again, and rise into the air.

Next, the man takes the banana. Holding it with his tongs, he lowers it into the liquid nitrogen container for half a minute. When he takes it out of the liquid, he grips it in his gloved hand, and he picks up the board and a nail. Using the “Banana Hammer,” he pounds the nail right into the board. We ooh and ahh and applaud. I guess he won’t be giving out that banana as a prize.

Finally, he reaches for the bouncy ball and drops it in the liquid nitrogen container. After a minute or so, he fishes it out using the metal scooper. Picking it up, he turns around and throws it at the concrete wall behind him. I get ready to grab it when it bounces back toward the audience. But it doesn’t bounce. It shatters into many small pieces. I wonder if he’ll put the ball back together as the grand finale, but it doesn’t work that way, I soon find out.

Before he leaves, however, he has one final demonstration for us. He unpins the red rose from his lab coat lapel, dips it in the liquid nitrogen, and then bangs it on the table. Tiny red pieces of frozen rose petals fly across the table. I’m not sure if I’m supposed to clap or cry. As everyone around me begins to applaud, I hesitantly join in. Even if the rose incident doesn’t sit quite right with me, I decide that chemistry is indeed wonderful, and I’m going to learn more about it when I grow up.

Published in: on November 9, 2009 at 1:10 pm  Comments (3)  
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Diversity in the Scientific Work Force: Why?

Our recent U.S. Presidential campaign and election have been proclaimed “historic” because of the gender and ethnic diversity of the candidates. In the world of chemistry, we’ve also seen historic demographic changes in recent years, especially in the presence of women in the workforce. Half of today’s undergraduates majoring in chemistry are women.

The percentage of chemists (and other scientists and engineers) who are members of under-represented minorities, however, is still woefully low. Scientific societies and professional associations are devoting considerable resources to advance the cause of diversity.

So, diversity is a good thing and it’s necessary. Right?

I must confess that I have been skeptical in the past. As a scientist, I want to see research results before I’m willing to give new ideas my full blessing. Show me the data!

Click here to see the rest of my article, published this week on the Careers Blog of the American Chemical Society (ACS).

Published in: on April 29, 2009 at 8:15 am  Comments (1)  
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Great website about scientific process

I’ve been looking over some of the nominees for this year’s Webby Awards, and I came across an excellent site that illustrates how science works.  Developed by the Exploratorium, Evidence:  How Do We Know What We Know? was nominated for a Webby People’s Voice Award in both the “education” and “science” categories.  I especially liked the sections on “How Science Works” and “Can You Believe It?”

Published in: on April 28, 2009 at 9:02 am  Leave a Comment  

Will Scientists Leave Hedge Funds and Return to Science?

An article in today’s New York Times, “A Rich Education for Summers (After Harvard), caught my eye.  It talks about how Larry Summers worked (one day a week, earning nearly $ 5.2 million in two years) at a large hedge fund “advising an elite corps of math wizards and scientists.”

The company,  D. E. Shaw & Company, was founded in 1988 by David E. Shaw, then a computer science professor at Columbia University.  According to the NYT article, “As part of Shaw’s rigorous screening process — the firm accepts perhaps one out of every 500 applicants — Mr. Summers was asked to solve math puzzles. He passed, and the job was his.”

I’m disappointed that the world of science wasn’t able to attract and retain these brilliant individuals over the past two decades.  If they had put their creative and analytical minds to work investigating mysteries of nature rather than mysteries of high finance, I think we might be better off today.

I’m encouraged that the tide may now be shifting.  In fact, according to the Shaw Group website,  “the vast majority of [David Shaw’s] time is now devoted to his role as chief scientist of D. E. Shaw Research, LLC, in which capacity he leads an interdisciplinary research group in the field of computational biochemistry and personally engages in hands-on scientific research in that field. He also holds appointments as a Senior Research Fellow at the Center for Computational Biology and Bioinformatics at Columbia University and as an Adjunct Professor of Biomedical Informatics at Columbia’s medical school.”

Let’s hope that the values and traditions in the world of science (as compared to the values and traditions in the world of banking) do a better job of effectively channeling the talents, dreams, and energy of the next generation of bright students.

Published in: on April 6, 2009 at 4:41 pm  Comments (1)  
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Don’t Forget the Boys

Don’t forget the boys.  That’s the message in Kathleen Parker’s op-ed piece, “Bring the Boys Along: The White House Council Obama Forgot, in the Washington Post.

Although she makes a few snarky comments along the way (that’s one of the things that columnists need to do to keep up their readership), I agree with the main theme of her article.

As a society, we’ve done an excellent job in the past generation of increasing opportunities and expectations for girls.  Now it’s time to realize that boys need our help, too.

Parker refers to suicide rates, which are much higher for boys than girls, as one indicator of the need for attention to boys in our society.  She could also have pointed to graduation rates, incarceration rates, and lifespan statistics.

The author who has done the best job documenting this issue is Dr. Warren Farrell. His books, such as The Myth of Male Power, are thought-provoking and should be required reading in any class that addresses gender issues in American society.

The topic is fraught with political correctness, myths, and ideology, so it’s one that I rarely bring up.  As the father of four boys and as a man who’s spent quite a bit of time in a non-traditional role (i.e., primary parent), I have strong opinions on the subject.

However, it really would take an entire semester-long class to begin to explore the issue in a way that does justice to the topic.   It would take an entire lecture to just lay out the caveats, the apologies-in-advance, and the careful definitions of terms.  Only after that opening lecture would many listeners begin to put aside their ingrained beliefs and open their ears and minds.  (Just remember what happened to Larry Summers, then-Harvard-President, when he clumsily raised some questions about women-men differences in math and science.)

As a scientist who’s written frequently on the subject of women in chemistry, I’m well aware that there are many subtle societal messages that represent barriers for girls and women in science.  And some of the barriers aren’t so subtle.

Any good discussion needs some statistics, so here are a few for the chemistry profession:

  • The percentage of bachelor’s degrees in chemistry earned by women has risen from 29% in 1981 to 55% in 2007 (statistics from the National Science Foundation and  Chemical & Engineering News, 12/3/07). During the same period, the percentage of Ph.D.s earned by women increased from 16% to 38%.
  • The median starting salaries for women and men bachelors-degree chemists are essentially equivalent ($36,300 vs $37,000), as are the salaries for women and men masters-degree chemists ($49,000 vs $46,000).  (These 2007 statistics come from Chemical & Engineering News, 6/2/08.) The data for doctoral-degree chemists are more difficult to interpret, with some years showing parity and some years showing significant disparity.
  • These significant increases in the number of women studying chemistry have not yet translated into comparable numbers among the leadership of the chemistry community, especially in academe. According to 2007 statistics, just 15% of chemistry professors at the top 50 universities are women. (The breakdown by rank is 11% full professor, 22% associate professor, and 22% assistant professor).

Another good place to go when starting a discussion is to consult some of the scientific leaders who have thought deeply on this subject.  Among the scientists who have impressed me with their thoughtfulness and shaped my thinking are Geri Richmond, Dick Zare, Helen Free, and Jo Handelsman.  If you get a chance to hear or read their thoughts on women and science, I highly recommend it.

While there’s still plenty of work to be done in making the world of science more friendly for women (and for men who want to be involved parents), an even more important issue in the coming years is going to be finding ways to advance the education and opportunities of both girls and boys in American society.

Published in: on March 20, 2009 at 6:00 am  Leave a Comment  
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Will today’s financial meltdown be this generation’s Sputnik?

I owe my career path to a metallic sphere that weighed about 185 pounds and was slightly larger than a big beach ball. Launched by Russian scientists on October 4, 1957, Sputnik-1 had a profound effect on American culture, education, and science. As the first satellite in outer space, it shocked the American public and its political leadership. Fortunately, the Sputnik scare served as the catalyst for a strong and broad emphasis on science and engineering that influenced a generation of American students–including me.

I celebrated my second birthday while Sputnik was orbiting the earth in 1957. When I was in first grade, my class gathered in the back of the school auditorium to watch John Glenn’s historic space flight. My high school textbooks in physics (PSSC Physics) and chemistry (CHEM Study) were developed in the aftermath of Sputnik and adopted widely across the country. Although I realized early on (shortly after I got my first pair of glasses in second grade) that I wasn’t going to grow up to be an astronaut, I could become a scientist—an occupation that was highly respected and sought after in those days.

The post-Sputnik fervor, of course, didn’t last forever. As icons of American culture and success, the astronauts and scientists of the 1960s were replaced, forty years later, by Wall Street investment bankers and hedge fund managers. In 2007, according to a survey conducted by the Harvard Crimson, of the Harvard seniors graduating that year and heading directly to the workforce, half of them (47 %) were heading into jobs with consulting firms and financial-sector companies. Yes, you read that right—47%!!

I expect that the survey results in 2009 will be quite different.

Just as Sputnik shocked American society into re-evaluating its priorities, the current financial meltdown will be forcing similar re-evaluations by a generation of students. Where will America’s best and brightest students be heading over the next generation?

The stimulus bill being passed today on Capitol Hill includes significant new funding for science and technology. President Obama promised in his inaugural speech to “restore science to its rightful place.” If we slog our way out of the current financial crisis, the solutions to the looming crises of the next generation (e.g., health care, energy, and climate change) will all require science and engineering.

We’ll need bright, creative scientists and engineers, of course. But perhaps more importantly, we’ll need a general public and citizenry that values and rewards innovation, invention, and success in areas other than just financial services.

It’s time for STEM (Science, Technology, Education, and Math) leaders and educators to make a difference again in the future of our country. It’s time to “step up to the plate.” And I don’t mean home plate on a baseball field. Forget that tired, old sports metaphor. I’m referring to the “plates” we’ll find in laboratories, nature, and classrooms. It’s time to step up to agar bacterial plates, tectonic plates, and thin layer chromatography plates.

Published in: on February 13, 2009 at 9:21 am  Comments (3)  

Kindergarten Chemistry

In his inaugural address, President Obama thrilled scientists across the country by simply uttering the following phrase:  “We will restore science to its rightful place.”

What a relief! The last eight years have been bleak for many scientists, as the Bush administration seemed to place ideology over scientific fact all too often. A good overview of scientists’ attitude can be found in this January 21st New York Times article, Scientists Welcome Obama’s Words.”

Science will clearly play a more important role in the Obama administration. It’s about time. Science and technology have a great deal to offer on policy issues such as climate change, energy, and health care. Encouraging scientists and engineers to help on these issues is certainly one of the things that Obama meant when he referred to science’s “rightful place.”

But that’s not the only “rightful place” where science must return.

I did my small part last week, when I helped restore science to one of its most important rightful places–the Kindergarten classroom.

As a Christmas gift to my godchild, a bright and curious five-year-old girl, I offered to visit her class to do some hands-on science activities. When my sons were in elementary school, I enjoyed doing this once or twice every year at their school. However, it’s been more than five years since I stepped into a classroom. It’s definitely time to restore science to its rightful place…

I was just as excited as the students were when we began our activity last week. We did an activity that uses red cabbage as an acid-base indicator. You just rub the red cabbage leaf on an index card to leave a big reddish-purplish smudge. Then, you can dip a Q-Tip in a common household acid, such as vinegar (acetic acid) or lemon juice (citric acid). Swiping the moistened Q-Tip across the smudge will reveal a color change. You can also dip a Q-Tip in a common household base (a mixture of water and baking soda or Alka-Seltzer works well) and repeat the experiment to get a different color change.

We experimented with other plant materials–from carrots to radishes to hydrangea petals. Some gave us wonderful color changes, and others gave us no change.  We talked about making observations, making guesses, and doing experiments–the scientific method.

At the end of the class, I asked all scientists in the room to raise their hand. With a little prodding, every Kindergartner (and the teacher and I) raised a hand.

Science was restored to its rightful place.


Want to try the experiment yourself? Here’s a copy of the information I sent home with the students that evening. (I printed the handout on goldenrod-colored paper, which also undergoes some fascinating color changes when you try the same experiment.)


“Science is Fun”

In Mrs. A’s class today, we did some hands-on science experiments involving chemistry and color changes. We learned about some household acids (lemon juice, vinegar, soda pop) and bases (baking soda, Milk of Magnesia). We used red cabbage to make an acid-base indicator that can be used to test pH, a measure of acidity.

pH measurement can be important in many areas of life. If you watch your favorite TV show or movie carefully, you just might start seeing acid-base chemistry in action:

  • Medicine — Blood pH is a routine medical test. It’s part of the “blood gas” test the ER doctors always seem to want on their patients.
  • Cosmetics — Watch those ads carefully. Is your shampoo “pH-balanced?”
  • Food – Acid indigestion? Eat too much of that rich food? You might want to use “Tums” (a base) to take care of that extra stomach acid.
  • Forensic science – Those CSI investigators can tell you all about acids, bases, and pH.
  • Recreation — Swimming pools and hot tubs must be maintained at a constant pH. In those movies set in Southern California, the cute guy that takes care of those pools seems to always be kneeling by the side of the pool testing its pH.

Today’s activity is just one of dozens of fun “kitchen chemistry” experiments that you can do with safe materials that are readily available at your grocery store. If you want to try some of these experiments in your own home, there are many resources available. Here are some to get you started.

Resources on the Internet

One of the handiest sources for wonderful experiments is the World Wide Web. Here are two sites that I highly recommend.
This site, from the Exploratorium (San Francisco’s science museum), is perennially voted one of the best science sites on the web.
The website of the American Chemical Society (ACS) is a rich resource of information about chemistry. The webpage listed here will point you towards dozens of science activities for children (and their adult helpers). The red cabbage experiment that we did today is adapted from the activity called “Lose the Indicator Blues.” To go directly to the page for this activity, use this address:

Published in: on February 5, 2009 at 11:25 am  Comments (20)  
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January 22 is “Thank Your Mentor Day”

Here’s a link to one of my blog articles on the ACS Careers blog:

Out of my high school graduating class of 400 students, three of us went on to get Ph.D. degrees in chemistry—an amazing proportion that’s a factor of 10 greater than expected. Was it something in the water?

No. It was Mr. Sturtevant, our chemistry teacher. He was enthusiastic, creative, and passionate about chemistry. He treated all his students (he called us his “little chemists”) with a respect that let us know we were on the cusp of young adulthood. more

Published in: on January 22, 2009 at 10:31 am  Comments (4)  
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