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Anne Marie Helmenstine, Ph.D.

Anne Marie's Chemistry Blog


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This Day in Science History - June 2 - Nils Sefström

Sunday June 1, 2014
June 2nd is Nils Gabriel Sefström's birthday. Sefström was the Swedish chemist who re-discovered the element vanadium in 1830.

Vanadium was originally discovered by the Mexican mineralogist Andrés Manuel del Río in 1801 where he named his discovery panchromium, meaning "all colors" because it formed many colorful compounds. He eventually went with the name erythronium, where erytho- means red, because of the bright red crystals formed by the oxide of the new element. He sent samples to his European colleagues to verify his discovery but they mistakenly identified the crystals to be chromium and he gave up his claim.

Twenty nine years later, Sefström discovered the same bright red crystals and believed he found a new element that he named vanadium after the Scandinavian goddess of love, Vanadis. His discovery was verified and vanadium became the official name of the element.

Find out what else occurred on this day in science history.

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The Singing Spoon

Sunday June 1, 2014
Make a spoon sing using dry ice. (Donovan Govan)Do you know how to make an ordinary metal spoon sing or scream? The easiest way is to press the spoon against a rapidly sublimating material, like dry ice.

Singing Spoon Video | See how it works

This Day in Science History - June 1 - Werner Forssmann

Saturday May 31, 2014
June 1st marks the passing of Werner Forssmann. He was a German physician who first inserted a catheter into a person directly into the heart. He was also the first person to have this procedure done. As an intern in cardiology he believed drugs could be administered to the heart with a catheter without killing the patient. To prove it could be done, he inserted a catheter in his own antecubital vein and, catheter dangling from his arm, proceeded to climb two flights of stairs to get an x-ray to document the catheter's position in his right atrium.

This stunt earned him the ire of his superiors and he faced disciplinary action and changed his internship to urology. During World War II, he served in the German army as a doctor until he was captured and sat out the war in a prisoner of war camp. After the war, he worked as a lumberjack and country doctor until in 1956 he was surprised to receive part of the 1956 Nobel Prize in Medicine for his medical school "stunt".

Find out what else occurred on this day in science history.

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Homemade Dippin Dots Ice Cream

Saturday May 31, 2014
Dippin Dots Ice Cream (RadioActive)Did you know you can make your own Dippin Dots ice cream? It's actually a simple variation of the classic liquid nitrogen project. You can make these for fun, part of a science project or dessert! Here's what you do...

How TNT Pop Its Snappers Work

Saturday May 31, 2014
TNT Pop Its Snappers (Anne Helmenstine)In case you were wondering, TNT Pop Its don't contain TNT. That is simply their brand name. Pop Its are trick noisemaker "rocks", commonly seen around the 4th of July and other holidays, that pop when they are stepped on or thrown against a hard surface. They look like little paper-wrapped rocks, which, in fact, is what they are.

The rock is rock or sand that has been soaked in silver fulminate. Silver fulminate (like mercury fulminate, which would be toxic) is explosive. However, the quantity of fulminate in Pop Its is very small so the little exploding rocks are safe. Fulminates are easily prepared by reacting metal with concentrated nitric acid. You don't want to go making this in any quantity yourself because the fulminate is shock sensitive and pressure sensitive. However, if you decide to make do-it-yourself Pop Its, the silver fulminate is more stable if flour or starch is added to the crystals during the filtering process.

This Day in Science History - May 31 - European Space Agency

Friday May 30, 2014
On May 31, 1975 eleven European nations pooled their resources and formed the European Space Agency. The ESA was formed to advance scientific discovery and exploration. They partner with NASA, the Russian Federal Space Agency and JAXA on projects like the Hubble Space Observatory and International Space Station. They compete on the satellite launching market with the Ariane and Soyuz launch vehicles that are launched from French Guiana, near the equator. Happy birthday ESA!

Find out what else occurred on this day in science history.

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Blue Color Change Demo You Can Do at Home

Friday May 30, 2014
Copper complexes often are vivid blue. (Anne Helmenstine)You don't need a chemistry lab to perform a dramatic color change chemistry demonstration. Make a pale blue solution. Add another chemical and watch the solution form a precipitate and turn milky sky blue. Continue adding the color and watch swirls of vivid blue form, until finally the entire solution turns deep translucent blue.

Chem Demo Materials

You only need water and two household chemicals for this project:
  • hot tap water
  • copper sulfate
  • household ammonia
I used Root Kill™, which states on its label it is copper sulfate. Some pool treatments and algicides consist of copper sulfate, but read the ingredient list to make certain. Ammonia is sold as a common household cleaner. If you can't find pure dilute ammonia, try a glass cleaner that contains ammonia.

Perform the Color Change Demo

  1. Dissolve a spoonful of copper sulfate in a cup of hot water. The proportions are not critical, but you want a high enough concentration of copper sulfate to get a blue color.

  2. Stir in a small amount of ammonia. See the swirls of milky pale blue? The blue solid will settle out of solution if you allow it to sit undisturbed.

  3. Adding more ammonia will start to turn the solution deep blue -- much brighter than the original copper sulfate solution. When the reaction goes to completion you'll end up with a translucent blue liquid.

What Happened?

Ammonia and copper sulfate initially react to precipitate copper hydroxide. Additional ammonia dissolves the copper hydroxide to form a vivid blue amino-copper complex. The cuprammonium solution could be used to dissolve cellulose as part of one method of producing Rayon.

Blue Bottle Color Change Demo | More Home Chem Projects

How an Ice Cream Soda or Float Works

Friday May 30, 2014
An ice cream soda or ice cream float (called a spider in Australia and New Zealand) is made by adding soda pop or seltzer to ice cream. Some people add flavoring, like chocolate syrup, or a little milk. However you make it, as soon as the soda hits the ice cream you get fizzy, frothy, tasty bubbles.

Do you know how it works? It's basically the same as what is going on with the Mentos and Soda Fountain, except not as messy. You are knocking the carbon dioxide in the soda out of solution. Bubbles of air in the ice cream provide nucleation sites around which carbon dioxide bubbles can form and grow. Some ingredients in the ice cream lower the surface tension of the soda so the gas bubbles can expand, while other ingredients trap the bubbles in much the same way as small amounts of protein in seawater trap air to form seafoam.

I like all types of floats, including black cows (coke floats with cola and vanilla ice cream), brown cows (root beer float with root beer and vanilla ice cream), and purple cows (grape soda and vanilla ice cream), but you can use other ingredients. Here's a recipe for a coffee cola Float, which is bubbly and caffeinated and therefore a double-win:
  • 2-1/2 cups coffee (room temperature or chilled)
  • 2/3 cup light cream or milk
  • coffee, chocolate or vanilla ice cream
  • cola
Mix the coffee and cream or milk, pour it into glasses, add scoops of ice cream, and top it off with cola. You can garnish it with whipped cream, chocolate covered coffee beans, or a little coffee powder or cocoa.

This Day in Science History - May 30 - Aleksei Leonov

Thursday May 29, 2014
May 30th is Aleksei Arkhipovich Leonov's birthday. Leonov was one of the original team of Soviet cosmonauts and was the first man to leave the spacecraft and take a spacewalk. He left the Voskhod 2 spacecraft and spent 12 minutes floating alongside attached by a tether. He practiced free-fall maneuvers, made observations and took a short motion picture. When he attempted to return to the capsule, he found his suit had overpressurized to the point where he couldn't fit though the hatch. He had to bleed off the excess air to fit again.

He was also the commander of the Soviet half of the first joint US/USSR space mission, the Apollo-Soyuz rendezvous. Find out what else occurred on this day in science history.

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How to Remove Fluoride from Drinking Water

Thursday May 29, 2014
Most people are aware there is a controversy surrounding fluoridation of public drinking water. Some people want it removed; some people want to add it to their unfluoridated water. Here is information on how you can remove fluoride from water, as well as a look at what types of filtration don't remove fluoride and a list of foods and products that add fluoride to your diet. You can use it as a guide to help remove fluoride or as a way to preserve or supplement fluoride... Learn about fluoride filtration
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