How Things Work
How To Set a World Record
Have you ever wanted to set a world record? Here is what you need to do!
Are Copper Bowls Better for Whipping Egg Whites?
Using a copper bowl makes it more difficult to overbeat egg whites. Other bowl materials don't offer this advantage. In this article, your Guide explains the principle behind this cooking phenomenon.
Before You Buy Gasoline
This is a guide to help you choose the best gasoline for your auto, with quick 'what you need to know' facts. There is information about octane ratings, additives, reformulated and leaded fuel, and links to sites offering complementary or comprehensive information.
Best of the About Chemistry Forum
About Chemistry's Forum hosts some interesting and educational discussions. This is a collection of some of the best threads.
Biodiesel from Vegetable Oil Tutorial
As the price of diesel continues to climb, you may wish to consider making your own diesel from cooking oil, called biodiesel. It's easy and could save you money.
Can a Candle Burn in Zero Gravity?
Can a candle burn in the absence of gravity? Here's the answer to this frequently asked question about fire.
Can You Drink Too Much Water?
It's important to drink plenty of fluids, but can you overdo it? Learn the truth about water intoxication and hyponatremia.
Can You Use Laundry Detergent in the Dishwasher?
Yes, you could put laundry detergent in your dishwasher. Should you? Probably not. Here's why.
Can Your Hair Turn White from Fright or Turn Gray Overnight?
Is it true your hair can turn white from a bad scare or that your hair can turn gray overnight? Learn about your haircolor and get the answer to the question.
Wintergreen Lifesavers aren't the only candies that can make a spark in the dark. Take an in-depth look at the mechanism behind this special chemiluminescence caused by friction.
Carbon 14 Dating
Here's a worked example of the calculation for carbon 14 dating of organic material. The same principle can be applied to other isotopic ratios used to estimate age.
Carbon Monoxide Detectors
Learn why carbon monoxide is dangerous to your health and how carbon monoxide detectors and alarms work.
Chemicals for Hangovers
A hangover is Nature's way of reminding you that alcohol is not good for your body. Having said that, there are some substances that will reduce the damage or lessen the discomfort.
Chemistry of Autumn Leaf Color
Why do leaf colors change in the fall? What causes the different colors? It's mostly a matter of photochemistry rather than of temperature. Find out more!
Chemistry of Counterterrorism
Learn how chemistry is used in the war against terrorism. Topics include forensic science, sampling, detection, countermeasures, and use of dogs. There are links to centers specializing in counterterrorism and to government agencies.
Chemistry of Hard and Soft Water
Do you have hard water or soft water? Both? Do you know why? Get the definitions for hard and soft water, learn about their chemistry, and examine the pros and cons of each type of water.
Cloud in a Bottle Demonstration
Here's a quick and easy science project you can do: make a cloud inside a bottle. This simple project uses water vapor and smoke from a match to help form a cloud.
Colored Glass Chemistry
Have you ever wondered how glass is colored? Here's a table of common colorants and a description of processes used to color glass.
Cut Flower Preservative Recipes
It's easy and economical to make your own cut flower preservative. Adding floral preservative will help keep your flowers beautiful much longer than if you simply filled a vase with water.
Learn about the insect repellent called DEET. See its chemical structure, find out how it works, get information about the risks of using DEET, and find out how to reduce your need for bug spray.
Disappearing Ink Instructions
Learn how to make blue or red ink that will disappear after exposure to air. Tips for restoring the color and an explanation of the acid-base chemistry of the reaction are also included.
Do You Burn More Calories when you Think Hard?
Find out how many calories you burn when thinking and how it compares with the energy expended by physical exercise.
Does Bottled Water Go Bad?
Most bottled water has an expiration date stamped on the bottle, but does the bottled water actually go bad? If so, how long is bottled water good? Here's the answer to this common question.
Does Eating Turkey Make You Sleepy?
Find out why everyone wants to take a nap after Thanksgiving Day turkey dinner. Let's talk turkey and learn about L-tryptophan and carbohydrate metabolism.
Does Ice Melt Faster in Water or Air?
Do ice cubes melt faster in water or in air? If you watch ice cubes melt, it may be hard to tell whether they melt faster in water or air, but if the water and air are the same temperature, ice melts more quickly in one than in the other.
Elements in the Human Body
Find out what elements are in the human body and what these elements do.
Firework Periodic Table
Use this special periodic table to find out what elements are found in fireworks and how they are used. Just click on an element to learn more.
Fortune Teller Miracle Fish
If you place the plastic Fortune Teller Miracle Fish in your hand it will bend and wiggle. You can decipher the movements of the fish to predict your future. The movements of the fish are a result of the chemical composition of the fish.
Fruits That Ruin Jell-O
If you add certain fruits to Jell-O or other gelatin desserts, the gelatin won't set up. Here's a look at which fruits have this effect and what happens that causes them to ruin Jell-O.
Gasoline & Octane Ratings
This article from your About Guide discusses what octane ratings are, how they are calculated, and how to determine the best octane rating to use. There are links to gasoline and alternative fuel sites, as well as to definitions and molecular structures.
Hair Color Chemistry
Over 75% of women and a growing percentage of men color their hair. Learn about natural haircolor and find out what happens when you bleach hair or use temporary or permanent haircolor.
Learn the chemistry behind how hair detangler works and get recipes to make your own homemade hair detangler.
History of Matches
Fire may have been around since the dawn of civilization, but matches are a fairly recent invention. Learn about the somewhat gruesome history of the chemical or friction match and how antimony and phosphorus are used to start fire.
Home and Garden pH Indicators
Here's a list of common household substances and garden plants that can be used as pH indicators. Many of the active molecules, expected color changes, and pH ranges are listed.
How Blueprints Work
A blueprint is a paper-based reproduction of a drawing, usually a technical drawing, such as an architect or engineer would use. Learn what blueprints are made from and how they work.
How Detergents Work - Chemistry of Surfactants
Learn about the chemistry behind the cleaning power of detergents.
How Do Disposable Diapers Work? Why Do They Leak?
Learn about the polymer in disposable diapers, sodium polyacrylate. Find out how the polymer absorbs water and why diapers leak.
How Do Lightsticks Work?
Find out how lightsticks or glowsticks work. Learn about the chemistry behind the process and get on-line purchase information. This article also explains how to make glow sticks last longer or become brighter!
How Do Mood Rings Work?
Mood rings have a stone that is supposed to change color to show your emotions. Do they work? If so, do you know how? Here's your chance to find out.
How Do Pencil Erasers Work?
Learn about the different materials used as pencil erasers and how they work.
How Do Plants Make Food? How Photosynthesis Works
Photosynthesis is the name for the set of chemical reactions used by plants and other organisms to make food from sunlight, carbon dioxide, and water. Here's a look at the process and study questions to help make sure you understand the key concepts.
How Do Pop Rocks Candy Work?
Find out how pop rocks candy works and whether or not it's true your stomach will explode if you wash down pop rocks with soda.
How Do Pregnancy Tests Work?
Learn how blood tests and home pregnancy urine tests work, how early they can be used, and some reasons for false positive and negative test results.
How Do Safety Matches Work?
Learn about how safety matches work and why they are considered 'safe'.
How Do Smoke Detectors Work?
Find out how ionization and photoelectric smoke detectors work. Then determine which type is better for your needs. Links are supplied to give you more information about fire safety, tips for installing a smoke detector, and answers to common smoke detector questions.
How Do Sunless Tanning Products Work?
This article discusses bronzers, self-tanning lotions and sprays, tanning accelerators, and pills. Learn how these products work and find out why tans fade.
How Do Trick Birthday Candles Work?
You blow them out, but these candles re-light themselves. Magic? No, it's simple chemistry!
How Does Borax Clean?
Borax is used as a multipurpose cleaner and bleach. How does it work? Learn how the chemistry of borax relates to its cleaning power. These same properties are also associated with certain health hazards.
How Does Soap Clean?
You may use it every day, but do you know how it works? Learn about emulsions, micelles, and soap scum! Then check out links to sites about bubbles, soapmaking, and the regulation of soap chemistry.
How Does Stainless Steel Remove Odors?
Have you heard about the kitchen tip in which you rub your fingers across the blade of a stainless steel knife to remove odors from onions, garlic, and fish? You have now! Learn about the chemistry behind this interesting bit of cooking magic.
How Febreze Works
Does Febreze remove odors or merely mask them? Here's a look at how Febreze works, including information about its active ingredient, cyclodextrin, and how the product interacts with odors.
How Fireworks Work
Firecrackers, sparklers, and aerial fireworks are all examples of fireworks. Here's a look at the different types of fireworks and an explanation of how they work.
How Fluoride Works
Fluoride is the fluorine ion added to toothpaste and dental rinse to help protect your teeth from cavities. Here's how fluoride works.
How Jell-O Works
Jell-O gelatin is a tasty jiggly treat that results from a bit of chemistry kitchen magic. Here's a look at what Jell-O is made from and how Jell-O works.
How Popcorn Pops
Popcorn pops because each popcorn kernel is special. Here's a look at what makes popcorn different from other seeds and how popcorn pops.
How Sunscreen Works
Find out how sunscreen works, what an SPF rating means, the difference between sunscreen and sunblock, and how to protect yourself from both UV-A and UV-B radiation.
How To Color Fire
Have you ever wanted to color fire? Here are simple, nontechnical instructions for making your own colored flames. Add extra interest to your fireplace or campfire!
How to Make Aspirin - Acetylsalicylic Acid
Learn how to synthesize aspirin, acetylsalicylic acid, from salicyclic acid. Get information about the history of aspirin, the effects of salicylates, and see the structures of the reactants.
How to Make Moonshine
Moonshine is a liquor made from fermented corn. Learn about distillation, condensation, and how this alcoholic beverage is made.
How to Make Red Cabbage pH Indicator
Make your own pH indicator solution! Red cabbage juice indicator is easy to make, exhibits a wide range of colors, and can be used to make your own pH paper strips.
How to Prepare Gases
Here are simple instructions for preparing common gases from ordinary chemicals. The gases include carbon dioxide, oxygen, nitrogen, methane, nitrous oxide, chlorine, and several others.
How To Remove Fluoride from Drinking Water
This is a list of methods that can be used to remove fluoride from drinking water. There's also a list of methods that do not remove fluoride and suggestions for ways to minimize fluoride exposure. References for the fluoridation controversy are included.
If I Leave My Goldfish in the Dark, Will it Turn White?
Learn about pigment biochemistry and find out whether your goldfish will turn white if you leave it in the dark long enough.
Is There Really a Chemistry of Love?
Sweaty palms and a pounding heart don't just happen! It takes complex biochemistry to give you the symptoms of being in love. And lust. And security. Chemistry may even play a role in falling out-of-love. Get some of the details here, with links for further study.
Mood Ring Science - Video
Learn about the chemistry behind how mood rings work. This video discusses the crystals used in mood rings, the moods that are associated with the colors of the ring and whether or not mood rings can accurately predict your mood.
Light Stick Colors
This article lists some of the fluorophors that are used to give light sticks different colors. The oxalate chemiluminescent reactions are introduced.
Mad Cow Disease - What You Need to Know
When it comes to Mad Cow Disease, it's difficult to separate fact from fiction and hard data from supposition. Part of the problem is political and economical, but a lot of it is based in biochemistry. Here's a summary of what you need to know.
Make Your Own Magic Rocks - Chemical Garden
Learn about the chemistry behind magic rocks and make your own chemical crystal garden.
Melting Snow & Ice with Salt
You know salt is sprinkled on roads and sidewalks to melt ice and prevent it from refreezing, but do you know how it works? Learn about freezing point depression and colligative properties and find out about the pros and cons of several de-icers.
MRI Reaction with Tattoos
Is a burning reaction between a tattoo and magnetic resonance imaging (an MRI) based in fact or is it an urban legend? Here's the answer!
Natural Easter Egg Dyes
These are easy instructions for making your own natural Easter egg dyes, using fruits, vegetables, and spices.
Natural Mosquito Repellents
Looking for a natural alternative to synthetic chemical mosquito repellents? Find out which natural substances repel mosquitoes, how to avoid attracting them, and how to maximize the effectiveness of your repellent.
Pineapple and Jell-O
Have you heard that adding pineapple to Jell-O or other gelatin will prevent it from gelling? It's true. The reason pineapple prevents Jell-O from setting is because of its chemistry. Learn about what is in pineapple that causes this to happen.
Qualitative Analysis - Flame Tests
The flame test is a quick low-tech method of identifying an element by the color of light it yields in a flame. Learn how to perform this test and to interpret the results.
Re-Use the Turkey Thermometer
You can re-use the pop-up thermometer that comes with a frozen turkey. Here are easy instructions to re-set the thermometer, which you can then you for another turkey or for other types of poultry.
Relating Atomic Number to Atomic Mass - Isotopes
Higher atomic number doesn't imply higher atomic mass. At least not always! Sometimes one element of lower atomic number can have a higher atomic mass. Learn about the effect of isotopic ratios on atomic mass.
Ricin and RCA - Castor Bean Toxins
Learn about ricin and RCA, the two potent toxins from the castor bean plant. Information is provided about the action, symptoms, and treatment of ricin and RCA poisoning.
Searching for Extraterrestrial Life
There's some serious chemistry involved in the search for life on other planets (or gas clouds or asteroids or comets). However, other disciplines come into play as well, such as robotics, aeronautics, biology, geology, and economics. Here's an overview of how we search for ETs.
Silly Putty Chemistry
Learn about the history of Silly Putty, how it works, how to make your own, and what you can do to explore the interesting properties of this viscoelastic liquid.
Slime Step-By-Step Instructions
Slime is easy and fun to make, plus it only requires glue, borax, and water. Here are step-by-step instructions for making classic slime, complete with photos.
Smoke Bomb Instructions
You can easily make a smoke bomb using inexpensive materials to produce safe smoke.
Smoke Machine Chemistry
Have you ever wondered how smoke machines work or wanted to make your own smoke or fog? Here's your chance to find out how it works. There are separate sections for each type of non-toxic smoke generator, together with important safety tips.
Here are answers to common questions about snowflakes. Learn how snow forms, what shapes snowflakes take, why snow crystals are symmetrical, whether no two snowflakes really are alike, and why snow looks white!
Learn how to make your own sparklers, for Independence Day or New Years Day fun. Use your understanding of chemistry to color the sparks.
Spiders in Space
Columbia's STS-107 carried Australia's first animals into space. Learn about the Columbia spider experiment and the Skylab 3 experiment and visit links to ground-based research and space exploration.
Sports Drinks - Better than Water?
Are you exercising or sweating away under a summer sun? Find out what beverage to drink to get and stay hydrated. Do you think water is best? Are sports drinks worth the money? What about a beer? Here's what you need to know.
Tattoo Ink Chemistry
Tattoo inks aren't regulated by the US FDA, so what you don't know can hurt you. This 3-part article examines the pigments, carriers, and other chemistry-related issues concerning tattoo inks and their toxicity. Instructions for making your own tattoo ink are provided.
Touching Dry Ice
Dry ice is solid carbon dioxide, which is extremely cold. You should wear gloves or other protective gear when you handle dry ice, but have you ever wondered what would happen to your hand if you touched it? Here's the answer.
Vodka in the Freezer
Why doesn't vodka freeze when you put it in the freezer? The answer to the question has to do with the chemical composition of vodka and a phenomenon known as freezing point depression.
Urine Chemical Composition
Urine is a liquid produced by the kidneys to remove waste products from the bloodstream. Human urine is yellowish in color and variable in chemical composition, but here is a list of its principal components.
When you burn a candle the wax molecules in the candle react with oxygen in the flame and are converted into water and carbon dioxide. Learn more about what happens during wax combustion.
Ways to Lower Fluoride Exposure
Fluoride isn't only found in toothpaste and water. There are many everyday sources and several steps you can take to lower your exposure.
What Are Olympic Medals Made Of?
What do you think Olympic medals are made of? Are the gold medals really gold? They used to be solid gold, but now Olympic gold medals are made from something else. Here's a look at the metal composition of Olympic medals and how the medals have changed over time.
What Are the Elements in the Human Body?
Do you know the chemical composition of the human body? Here's the list of elements, given in percentage according to weight.
What Causes Brain Freeze?
If you've ever experienced a sudden stabbing pain in your forehead when eating ice cream or enjoying a cool drink then you know what brain freeze is. Do you know what causes brain freeze or how you can stop the pain?
What Is a Neutron Bomb?
Learn what a neutron bomb is, how it works, and about a neutron bomb's strategic uses.
What Is Activated Charcoal and How Does it Work?
Activated charcoal isn't the same as your average barbeque briquette! It's a special type of carbon. Learn what activated charcoal is and why it is used in filters and medicines.
What Is Bleach and How Does It Work?
Learn what a bleach is, get examples of different types, and find out how bleach works.
What Is Dry Ice?
Do you know what dry ice is? Learn about dry ice and find fun projects that use dry ice.
What Is Gorilla Glass?
Gorilla Glass is the thin, tough glass that protects cell phones and other portable electronic devices. Here's a look at what Gorilla Glass is and what makes it so strong.
What Is in Chewing Gum?
Learn about the ingredients in chewing gum and find out whether it's true gum stays in your stomach seven years if you swallow it.
What Is Radioactivity? What is Radiation?
Learn about natural and induced radioactivity and alpha, beta, and gamma radiation.
Turning Lead into Gold
In many animals Jacobson's organ is responsible for sensitive chemical detection and pheromone communication between members of the same species. Is Jacobson's organ responsible for the sixth sense in humans?
What Is Reverse Osmosis?
This handy technique is used to desalinate seawater and purify bottled water. Find out how it works!
What Is Soap and How Is it Made?
Soap is a salt made from a chemical reaction between fat and sodium or potassium hydroxide. This article explains the saponification reaction both in words and with structure diagrams and provides links for further information.
What Is the Difference Between Baking Powder & Baking Soda?
Learn about the difference between these two common cooking ingredients, the effect of substitutions, and find out how you can use baking soda to make your own baking powder.
What Is the Greenhouse Effect?
Learn what the greenhouse effect is and how it is related to climate.
What Is the Most Abundant Element?
The elemental composition of the universe and the earth's crust are very different! How different? Take a look...
What Is the Smelliest Chemical?
There are some man-made chemicals with a stench well beyond the gentle perfume of dirty gym socks and skunk spray. Do you know the names of these super-stinkers?
What is the State of Matter of Fire?
What is the state of matter of fire or flame? Is it a liquid, solid, or gas? Learn the answer to this question and get information about the chemistry of fire.
What Is the Wavelength of Magenta?
Have you ever tried to find the color magenta on the visible spectrum? You can't do it! There is no wavelength of light that makes magenta. So how do we see it? Here's the answer to the question.
What Materials Glow Under a Black or Ultraviolet Light?
Black lights emit ultraviolet radiation, giving certain materials an eerie glow. Which materials? You can do a little experimental research or you can check out this list!
What Temperature Does Water Boil?
At what temperature does water boil? What determines the boiling point of water? Here's the answer to this common question.
What Was Project Stormfury? Can Cloud Seeding Dissipate Hurricanes?
One way scientists have tried to lessen the severity of hurricanes is by seeding the clouds with silver iodide. This research program was Project Stormfury. Learn whether cloud seeding worked and why the program was discontinued.
What You Need to Know about Carbon Monoxide Detectors
Carbon monoxide poisoning is the leading cause of accidental poisoning deaths in America. Carbon monoxide detectors are available, but you need to understand how they work and what their limitations are in order to decide whether or not you need a detector and, if you purchase a detector, how to use it to get the best protection.
Why Are Babies Born with Blue Eyes?
Do you know the answer? It's a matter of chemistry as much as biology. I've included other factoids about eye color, including some that may surprise you.
Why Are Flamingos Pink?
Have you ever wondered why flamingos are pink or orange? You've probably heard it has something to do with what flamingos eat, but do you know what exactly it is that produces the color?
Why Do Clothes Wrinkle?
Learn why clothes wrinkle and how permanent press fabrics work. It's a matter of polymer chemistry and chemical bonding.
Why Do Cold Batteries Discharge Quickly?
Learn why batteries run down more quickly in cold weather, but hold their charge longer. There are links to find out more about batteries.
Why Do Leaves Change Color in the Fall?
Find out why leaves change color in the fall. Learn about the different pigments found in leaves and how bright autumn foliage is produced.
Why Do Onions Make You Cry?
Find out why you cry when you cut onions and how you can keep it from happening.
Why Do People Tap on Cans?
When you tap on the top of an unopened carbonated beverage you reduce the chance that it will spray all over you upon opening. Your About Chemistry Guide explains what happens and how it works.
Why Does Hair Turn Gray?
Have you ever wondered why hair turns gray as you get older and whether there is something you can do to prevent graying or at least slow it down? Here's a look at what causes hair to turn gray and some of the factors that affect graying.
Why Does Ice Float?
Learn about hydrogen bonding and density to understand why ice floats on water.
Why Does Salt Melt Ice?
You know that you can sprinkle salt on an icy road or sidewalk to help keep it from becoming icy, but do you know how salt melts ice? Take a look at freezing point depression to understand how it works.
Why Does the Pool Turn Blonde Hair Green?
Do you think it's the chlorine in the swimming pool that turns blonde hair green? Guess again.
Why Is It Harder to Rinse off Soap with Soft Water?
Soap lathers better in soft water, yet it's harder to rinse off than if you rinsed with hard water. Why? The answer lies in understanding the chemistry of soft water and soap.
Why Is Stainless Steel Stainless?
Learn about the chemistry of stainless steel. This article, from your About Guide, also includes descriptions of the different types of stainless steels, comments on passivation, and numerous links to sites offering related information.
Why Is the Ocean Blue?
Have you ever wondered why the ocean is blue? Have you ever wondered why the ocean is sometimes another color, like green, instead of blue? Here's the science behind the color of the sea.
Why Is the Ocean Salty?
Have you ever wondered why the ocean is salty? Have you wondered why lakes might not be salty? Here's a look at what makes the ocean salty and why other bodies of water have a different chemical composition.
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.
You and Your Cat and 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.
How Baking Soda Works for Baking
Baking soda helps make baked goods rise. Here's a look at the cooking chemistry behind how baking soda works.
Find out what it means when wine has wine legs or tears of wine.
Carbon Monoxide Detectors
Carbon monoxide detectors and carbon monoxide alarms protect you from toxic carbon monoxide gas. Learn how carbon monoxide detectors and alarms work.
What Are CDs Made Of?
A compact disc or CD is a device used to store digital data. Here is a look at the composition of a compact disc or what CDs are made of.
Tattoos are meant to be permanent, so they aren't easy to remove, but there are multiple methods that are used when a person wishes to have a tattoo removed.
Questions Kids Ask Chemistry Quiz
See if you know the answers to chemistry questions asked by kids. This multiple choice test covers general chemistry questions that apply to everyday life.
Turning Lead into Gold
Learn about transmutation, the holy grail of alchemy. Can one chemical be changed into another? Is it worth the effort?
Where on a Magnet Is the Magnetic Force the Strongest
Have you ever wondered where on a bar magnet the magnetic force is the strongest? Here is the answer to the question.
How Things Work
Learn about the science behind how things work. Get answers to frequently asked chemistry questions. Discover the science behind everyday phenomena and objects.