Category: Chemistry

Some Painful Truth

11/18/2021

Vicki Cobb
The Master Chef of Kids' Hands-on Science.

How well do you handle spicy food? Do you find food with a “kick” eye-watering and difficult to swallow? Or are you a real “fire eater;” nothing can be too hot?

A scientist, named Wilbur Scoville, figured out how to rank spicy food for hotness in 1912. The “heat” from peppers comes from a chemical called capsaicin (cap-say-sin). Pure capsaicin registers 16 million heat units on the Scoville scale. Zero is a sweet green, red or yellow pepper. A fresh, green Jalapeño (ha-la-pen-yo) is rated 2,500-8,000 units, a lot less hot than pure capsaicin.

The fact is that you don’t “taste” the heat. The sensation of heat comes from nerve endings in your tongue that respond to pain. Of course, these nerve endings are not just in your tongue. They are all over your body. So a good scientific question is: Can you “taste” hot sauce with, say, your wrist?

Check it out. Rub the inside of your wrist with a cut Jalapeño pepper or some hot sauce. Wait a few minutes. Feel the burn? Rinse off your wrist well with cool water.

Your tongue, of course, is much more sensitive than your wrist to many chemicals because it is always wet. Capsaicin, like a lot of other chemicals dissolves in water and reaches those nerve endings more quickly.

Another liquid that triggers your pain nerves in your tongue is soda. The carbon dioxide in the bubbles reacts with an enzyme in your mouth to form a weak chemical called carbonic acid. This acid fires the pain nerve endings in your tongue giving soda its “bite.”

How well can you tolerate this pain? Stick your tongue into a freshly opened glass of soda and hold it there. See how long you can keep it in the drink. One minute? Two minutes? Most people can’t last a minute. But maybe you’re tougher than that.

Some Mexican parents give their kids mixtures of sugar and red chili powder when they’re little to build up their tolerance for spicy foods. Do you think that people who love spicy food could also be champions at keeping their tongues immersed in soda? Design an experiment to find out at your next party.

Hot Stuff from Vicki Cobb on Vimeo.

atonguelashing from Vicki Cobb on Vimeo.

These videos were made from Vicki Cobb’s book We Dare You! She invites you to join her video project and make your own videos from her book and post them on the www.wedareyouvideos.com website.

Vicki Cobb is a member of iNK's Authors on Call and is available for classroom programs through Field Trip Zoom, a terrific technology that requires only a computer, wifi, and a webcam. Click here to find out more.

MLA 8 Citation
Cobb, Vicki. "Some Painful Truth." Nonfiction Minute, iNK Think Tank, 17 Oct. 2017, www.nonfictionminute.org/the-nonfiction-minute/some-painful-truth.

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How to Extinguish a Fire with a Bag of Potato Chips

11/4/2021

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Vicki Cobb

The Master Chef of Kids' Hands-on Science

Ever taste a stale potato chip? If not, here’s how to make one:

If you have an open bag of potato chips lying around, you can use them. Otherwise open a new bag.
Put a few fresh potato chips in a glass bowl in the sunlight and wait a day or two.
Taste one of these exposed potato chips.
Compare it to the taste of a chip from a brand new bag.

Big difference, no? It’s enough to worry a potato chip manufacturer. There are two things that make a potato chip stale. Can you guess what they are? Okay, I’ll tell you: Air (specifically oxygen in the air) and light. So potato chip manufacturers know that if they want to keep their chips fresh, they have to remove oxygen and light. How do they do that?

Take a close look at an opened bag of potato chips. It is foil-lined to make it light proof. An unopened bag is very puffy because it is filled with a gas. This puffiness protects the chips from breaking. But the gas in the bag is not air, which is a mixture of about 20% oxygen and 79% nitrogen. It is air without the oxygen, so it’s mostly nitrogen.

You can prove this. Oxygen is needed for fire to burn. If the air around a flame is flooded with nitrogen, the flame goes out. So you can use the gas in a bag of potato chips to put out a candle. Here’s how:

Light a candle. (Make sure you have an adult help you since this trick involves fire.)
Cut off the corner of a new bag of potato chips.
Gently squeeze some of the gas from the potato chip bag near the candle flame. If you squeeze too hard, it’s like blowing the flame out. You want it to go out because the nitrogen in the potato chip bag is quietly flowing into the space around the flame.

Now you know how to extinguish a flame with a bag of potato chips. You have also proved that there is no oxygen in a potato chip bag! And you know why!

Now go educate some grown-up.

Before being flooded with nitrogen

After being flooded with nitrogen

Vicki Cobb’s best known book is Science Experiments You Can Eat. This is the new third revision published in 2016.

Vicki Cobb is a member of iNK's Authors on Call and is available for classroom programs through Field Trip Zoom, a terrific technology that requires only a computer, wifi, and a webcam. Click here to find out more.

MLA 8 Citation
Cobb, Vicki. "How to Extinguish a Fire with a Bag of Potato Chips." Nonfiction Minute, iNK Think Tank, 2 Oct. 2017, www.nonfictionminute.org/the-nonfiction-minute/how-to-extinguish-a-fire-with-a-bag-of-potato-chips.

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Smelling Feet or Smelly Feet?

4/19/2021

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Dorothy Hinshaw Patent
Nature’s Animal Ambassador

Do your feet sometimes smell rotten? Do you wish you could toss out your shoes and start with a new pair? We make jokes about smelly feet, but smell and feet have a very different relationship among some insects.

Take butterflies. Have you ever watched a butterfly flit over a plant, gently touch its feet to a leaf, and then fly on to the next leaf? That butterfly isn’t being picky about where to land. It’s hunting for the right kind of leaf for laying its eggs. It’s “smelling” the leaf with its feet!

Actually, we need to qualify that statement a bit. Some writers will say the insect is “smelling” the leaf while others may write that it’s “tasting” the leaf. Smelling and tasting are forms of “chemoreception,” or sensing of chemicals. Smell usually refers to sensing from a distance while tasting generally means actually touching the nerve cells that sense a chemical.

We humans have cells in our noses that send messages to our brains about chemicals in the air. We call that our sense of smell. We have cells on our tongues that sense chemicals dissolved in liquid in our mouths. That’s taste.

That butterfly doesn’t have a nose, and its mouth is a long tube for sucking up nectar from flowers. Its chemoreceptors are elsewhere, like on its feet, around its mouth, and on its antennae. Most butterflies lay their eggs on the plants that the hatched caterpillars will eat. Some species are very specific about what plants their young can feed on. Take the postman butterfly, which lives in Central and South America. Its caterpillars can only survive on certain species of passionflower vines. Other species are poisonous to their offspring.

The female postman butterfly has dozens of special nerve cells on her feet called “gustatory sensilla.” Scientists think that when she touches gently down on a leaf, these cells can sense chemicals there that would be poisonous to her caterpillars. She avoids laying eggs on those leaves. But when she finds a plant that will nourish her young, she’ll alight and lay her eggs.

Now take your shoes off and move your feet around on the floor. The only nerve endings on your feet are ones that sense touch. But then, you don’t need to be able to smell the ground you walk on. Imagine how gross it would be if your feet could smell the insides of your socks and shoes—yuck!

In these photographs taken through a microscope, you can see the sensory sensilla (arrow) on the feet of the female butterfly on the right, which the male on the left doesn't have. From PLoS Genet. Jul 2013; 9(7): e1003620.

Above: Postman butterfly feeding Right: Female postman butterfly laying an egg. As you can see from these two photos, the postman butterfly can have a variety of color patterns. From Heliconius.org

A dog’s nose is 300 times more powerful than a human nose, so it’s no wonder that dogs use their incredibly advanced sense of smell to do some very important jobs. In Super Sniffers, Dorothy Hinshaw Patent explores the various ways specific dogs have put their super sniffing ability to use: from bedbug sniffers to explosive detectors to life-saving allergy detectors . . . and more. This dynamic photo-essay includes first-hand accounts from the people who work closely with these amazing dogs. For more information, click here.

Dorothy Hinshaw Patent is a member of iNK's Authors on Call and is available for classroom programs through Field Trip Zoom, a terrific technology that requires only a computer, wifi, and a webcam. Click here to find out more.

MLA 8 Citation
Patent, Dorothy Hinshaw. "Smelling Feet or Smelly Feet?" Nonfiction Minute, iNK
Think Tank, 23 Jan. 2018, www.nonfictionminute.org/the-nonfiction-minute/
Smelling-Feet-or-Smelly-Feet.

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Isaac Newton's Wonder Years

4/2/2021

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Kerrie Logan Hollihan
Teaching the Power of Wonder

   In spring 1665 a college student named Isaac Newton studied natural philosophy, what we call “science.” Back then, a good student could learn everything to know about the natural world. But plague, the Black Death, came to England. Cambridge University closed. Isaac went home to Woolsthorpe.

            For two years Isaac thought about his studies during four years at university. He’d always been thoughtful—not the best at games, making friends, or minding sheep. But everybody knew Isaac Newton liked to think. Folks told time by the sundial he’d drawn on a wall.

            Home at Woolsthorpe, Isaac’s learning about science and math bubbled up in his head like yeast rising in a loaf of bread.

            So... Newton unplugged. His mind roamed like that of an artist or composer. He was driven by the need to create—not paintings or symphonies, but questions.

            “Why do things always fall down?”

            “Why does the earth move around the sun?

            “Why doesn’t the moon fall onto the earth?”

            “Does everything ‘up there” work like things work ‘down here?’”

            Isaac Newton answered his questions with three science rules, Newton’s Laws of Motion.

            At Woolsthorpe, Newton grappled with the concept of moving objects. He worked out the math to find the area under curves. He called this math fluxions. Today we call this calculus, useful for launching rockets or tracking TV signals.

            Once back at Cambridge, Newton said nothing until he read someone else’s paper on fluxions. Newton published a better paper. Soon he was Cambridge’s top math professor.

            Isaac Newton wondered another twenty years. He played with prisms in a dark room and theorized that white light comprises the visible spectrum of red, orange, yellow, green, blue, indigo, and violet. He practiced alchemy and chemistry, looking for the legendary philosopher’s stone to turn base metals to gold. In 1687, Newton published our most important science book, the Principia.

            In the Principia, Newton showed how laws of gravity and motion work the same at great distances—far off in space, or in your classroom. We accept these ideas, but in 1687 many still had medieval beliefs that sun, moon, planets, and stars all traveled in their own crystal spheres.

            Yes, Newton wondered about A LOT:

Gravity
Forces
Mass
Inertia
Math
Motion
Light
God
???

Whatever interests you, I hope you’ll think about it—a lot! Like Isaac Newton, take time to WONDER!

Sir Isaac Newton was an English mathematician, astronomer, theologian, author and physicist who is widely recognized as one of the most influential scientists of all time and a key figure in the scientific revolution. Based on a portrait by Godfrey Kneller, 1702, via Wikimedia Commons

Sir Isaac Newton's own first edition copy of his Philosophiae Naturalis Principia Mathematica with his handwritten corrections for the twentieth edition. Photograph Andrew Dunn via Wikimedia Commons

Trinity College, the part of the University of Cambridge where Newton worked and lived. Library of Congress

This statue of the young Isaac Newton stands at the Oxford University Museum of Natural History. Look carefully around his feet for a hint on what he is wondering about. If you can’t figure it out, then read about Newton and gravity.
Wikimedia Commons

Featuring 21 hands-on projects that explore the scientific concepts Isaac Newton developed, Kerrie Logan Hollihan's Isaac Newton and Physics for Kids paints a rich portrait of the brilliant and complex man and provides readers with a hands-on understanding of astronomy, physics, and mathematics. A time line, excerpts from Newton's own writings, online resources, and a reading list enhance this unique activity book.

MLA 8 Citation
Hollihan, Kerrie Logan. "Isaac Newton's Wonder Years." Nonfiction Minute, iNK
Think Tank, 21 Feb. 2018, www.nonfictionminute.org/the-nonfiction-minute/
isaac-newtons-wonder years.

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Marie Curie: An Elite Player in the Science Game

3/6/2021

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Vicki Cobb
The Master Chef of Kids' Hands-on Science

In October, 1891, 23-year-old Manya Sklowdowska arrived in Paris to attend the Sorbonne, France’s great university. She had saved money, working as a governess to get there. She was determined to make the most of her studies in science and math. Right away she was noticed partly because she was Polish, although she had changed her first name to a French version, Marie, to fit in better. She always sat in the front row of all her classes because her French was not yet fluent and she didn’t want to miss anything. She also was one of only a few female students. In a university full of smart people, she worked hard to excel. She ultimately finished first in her class and went on to make major scientific discoveries.

What made Marie so single-minded and determined? Behind it all was a great love for science, a love she shared with her husband, Pierre Curie, whom she met in 1894. At that time, science was uncovering unimaginable truths in chemistry and physics. New discoveries were being made at a breath-taking pace. Science was like a game and it attracted many players. Why?

1.       There was a Nobel Prize for winners, those who discovered a big idea about the natural world. There was only one nature to discover but people came at it from many directions.

2.       It was collaborative—scientists shared their discoveries by publishing papers.

3.       It was competitive—the papers described procedures so that scientists could check each other’s work. It kept everyone honest. The best work got the most attention.

4.       The discoveries could be applied to solve problems for people. X-rays, light bulbs, phonographs, photographs, movies, and telephones would not have been possible without science.

5.       The biggest prize was the idea of the atom and its structure. Many scientists contributed to modern atomic theory, including Marie.

Marie Curie won the Nobel Prize twice for her work. At a time when women didn't even have the right to vote, she was a working mother of two daughters, a single mother after she was widowed in 1906, the founder of the Radium Institute for research and she brought the x-ray to the battlefield in WWI. She believed that science could save the world, that scientific discoveries belonged to everyone. And she refused to benefit financially from her discoveries. She lived by the highest principles of honesty and integrity. She was a true champion of the science game.

Young Marie Curie (left) with her father and sisters.

Marie and Pierre Curie with their daughter Irene.

Marie Curie's 1903 Nobel Prize portrait

Pierre and Marie Curie in their laboratory.

DK Biography: Marie Curie tells the story of the discoverer of radium, from her childhood in Warsaw, to her experiments with radioactivity in Paris, to her recognition as one of the preeminent scientists of her time.
Filled with archival photographs and amazing fact boxes, this biography paints Marie Curie as the brave and brilliant scientist that she was.

Vicki Cobb is a member of iNK's Authors on Call and is available for classroom programs through Field Trip Zoom, a terrific technology that requires only a computer, wifi, and a webcam. Click here to find out more.

MLA 8 Citation
Cobb, Vicki. "Marie Curie: An Elite Player in the Science Game." Nonfiction
Minute`, iNK Think Tank, 30 Jan. 2018, www.nonfictionminute.org/
the-nonfiction-minute/Marie Curie-An-Elite-Player-in-the-Science-Game.

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Some Painful Truth

How to Extinguish a Fire with a Bag of Potato Chips

Smelling Feet or Smelly Feet?

Isaac Newton's Wonder Years

Marie Curie: An Elite Player in the Science Game

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