Dr. Helmenstine's 2004 Chemistry Articles
05/02/04 - Briggs-Rauscher Oscillating Color Change Reaction
The Briggs-Rauscher reaction, also known as 'the oscillating clock', is one of the most common demonstrations of a chemical oscillator reaction. The reaction begins when three colorless solutions are mixed together. The color of the resulting mixture will oscillate between clear, amber, and deep blue for about 3-5 minutes. Let's try it!
04/26/04 - How to Grow Red Potassium Ferricyanide Crystals
Here are instructions for easy red monoclinic crystals. Don't let the 'cyanide' part of the chemical name put you off -- these crystals aren't edible, but neither are they more toxic than most other compounds.
04/21/04 - What Is the Volume & Chemical Composition of Blood?
Do you know how many liters of blood are in your body? How about what's in your blood? Let's learn about the chemistry of human blood.
04/05/04 - What Is Distillation?
Distillation is a common chemistry process used to separate materials by changing their states of matter. Learn more about how the process works and find out about different types of distillations.
03/24/04 - What Is the Most Poisonous Chemical Compound?
How poisonous something is depends a lot on how it's administered and several other factors, but this list will give you a general look at some of the most toxic substances known to man.
03/15/04 - What Is the Sweetest Compound?
Did you know there are sweeteners that are 200,000 times sweeter than table sugar? Take a look at this list to find out how your favorite sweetener rates.
03/12/04 - Element Symbol Matching Quiz
Here's a challenging matching quiz, using elements/symbols drawn from the entire periodic table, with an eye toward matches that tend to be confusing.
03/11/04 - Element Symbol Matching Quiz
Can you match the names of the elements to their corresponding symbols? Here's an easy quiz to test your skill, using 10 of the first 18 elements. Have fun!
03/07/04 - What Is Red Mercury?
Is it a secret, wildly explosive compound used to make deuterium-tritium fusion bombs for use by terrorists? Maybe there's a more conventional explanation...
03/01/04 - What Is the Most Bitter Compound?
I've had some scorched coffee that I'm sure should have qualified for this award, but it turns out there's a real answer to this question of taste. Do you know what it is?
02/29/04 - What Is a Mole and Why Are Moles Used?
No, we're not talking about the small burrowing mammal! Here's a look at a standard unit in chemistry and why it's used.
02/22/04 - Chemistry Fun with Pennies
Use pennies, nails, and a few simple household ingredients to explore some interesting properties of metals.
02/13/04 - What Are Some Careers in Chemistry?
Here's a nice long list of chemistry-related careers, along with a discussion on how your degree impacts your employment options.
02/11/04 - Old Element Names Quiz
There are several elements which have symbols that don't seem to correspond to their names. That's because the symbols come from old names for the elements. Here's a multiple choice quiz to test your knowledge of the element names.
02/10/04 - What Is the Difference Between Baking Powder & Baking Soda?
Learn about the difference between these two common cooking ingredients and find out how you can use baking soda to make your own baking powder.
02/05/04 - Make Ice Cream in a Baggie
Make a tasty treat and learn about freezing point depression, too! All you need are some basic ingredients and two ziploc baggies. Show me how...
02/03/04 - Chemistry Timeline
Find out who did what and when they did it. This timeline chronicles achievements in chemistry and in other disciplines (e.g., physics, mathematics) as they apply to chemistry.
01/30/04 - Crystal Growing - Troubleshooting Common Problems
Are you having trouble growing crystals? Before you throw out your solution, read this list of common problems and fixes.
01/29/04 - Element Symbols
It's easier to navigate the periodic table and write chemical equations and formulae once you know the symbols for the elements. Here's an alphabetical list of element symbols with the corresponding element name.
01/28/04 - How to Grow Great Crystals
Do you want to grow crystals, but you aren't sure where to start or what to do to make sure your crystals turn out well? Here's some basic information on crystal growing. I've provided links to recipes so you can start growing crystals. These instructions are general, so if your recipe calls for something special (like no vibrations or dark), be sure to follow those directions, too.
01/23/04 - You & Your Cat & Mad Cow Disease
Do you think you have a handle on the Mad Cow Disease issue? Here's a detailed guest article, written by microbiologist Eve Riser-Roberts, Ph.D., that may shake things up a bit for you. Although the article is slanted toward dangers in pet food, it contains a lot of controversial information pertaining to human risk and infection.
01/21/04 - What Is Chemistry?
Here's the long and short answer to this Frequently Asked Question.
01/20/04 - Make Frozen Bubbles
Use dry ice to freeze bubbles solid so that you can pick them up and examine them closely. You can use this project to demonstrate several scientific principles, such as density, interference, semipermeability, and diffusion.
01/18/04 - Boyle's Law
Here's an introduction to Boyle's Law, as well as a worked example problem and links to related resources.
01/16/04 - Why the Flu Vaccine Doesn't Work
A new study conducted by the CDC indicates that getting the flu vaccine doesn't protect you against cold, flu-like illness, or even the flu. Surprised? Here are some reasons why the vaccine may not work.
