Answers to Questions about How Things Work

These are questions an educated person should be able to answer relating to chemistry in the everyday world.

Chemistry is a big part of your everyday life. You find chemistry in daily life in the foods you eat, the air you breathe, your soap, your emotions and literally every object you can see or touch. Here's a look at some everyday chemistry.

Explanation of why copper bowls are used when whipping egg whites.

Can a candle burn in the absence of gravity? Here's the answer to this frequently asked question about fire.

Can hot water freeze faster than cold water? You may have heard this question and wondered how, if it's true, it could even be possible. Here's the answer to the question.

Can you cool a room by opening the refrigerator? It might be tempting to open the refrigerator door to cool off when it's hot, but will it really help? The answer depends on a few different factors relating to your refrigerator.

It's important to drink plenty of fluids, but can you overdo it? Learn the truth about water intoxication and hyponatremia.

Yes, you could put laundry detergent in your dishwasher. Should you? Probably not. Here's why.

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.

Find out how many calories you burn when thinking and how it compares with the energy expended by physical exercise.

Does adding salt lower the boiling point of water? You may have heard this and wondered if it was true. Here is a look at the science behind salt and boiling water.

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.

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 hard water boil at a higher temperature than normal water? Here's the answer to the question and the explanation behind it.

Have you ever wondered how the elements are named or why some elements have more than one name? Here's the answer to your question.

Find out if there are any elements left to be discovered and how they would be found.

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.

Make a smoke bomb that billows clouds of brightly colored smoke. This project is easy and safe enough to at home. Adult supervision is required.

Learn how to make your own sparklers, for Independence Day or New Years Day fun. Use your understanding of chemistry to color the sparks.

You can make fake snow using a common polymer. The fake snow is non-toxic, feels cool and wet to the touch, and looks similar to the real thing.

Fluoride isn't only found in toothpaste and water. There are many everyday sources and several steps you can take to lower your exposure.

Use this redox-based iodometric titration to determine the amount of Vitamin C or ascorbic acid in juice and other samples.

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.

Do you think chemical weapons smell terrible? You might be surprised to learn many are odorless or smell pleasant.

Learn about the polymer in disposable diapers, sodium polyacrylate. Find out how the polymer absorbs water and why diapers leak.

Mercury is an extremely toxic metal that is found in fluorescent light bulbs, mercury thermometers, and other household items. If you break a thermometer or a mercury-containing bulb, it's important to dispose of the mercury properly so that you don't accidentally poison yourself or contaminate the area with mercury.

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.

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.

Learn how a lightstick or glowstick works. Get information about cyalume and chemiluminescence.

A seed crystal is a small single crystal that you use to grow a much larger crystal from a saturated crystal solution. This is how you can grow a seed crystal yourself.

Do you know the difference between a mixture and a compound? Combine iron and sulfur to make a mixture and then react them to form a chemical compound.

You can easily make a smoke bomb using inexpensive materials to produce safe smoke.

Make your own invisible ink so you can write and reveal secret messages. Get information about inks that are activated by heat, chemical reactions, and ultraviolet light.

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 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.

Make your own version of Floam, a type of slime that contains polystyrene beads so that you can mold it into shapes.

What is better than regular slime? Slime that glows in the dark, of course! This is an easy and fun project that is suitable for kids.

Sugar crystals are also known as rock candy since the crystallized sucrose resembles rock crystals and because you can eat your finished product. You can grow clear sugar crystals with sugar and water or you can add food coloring to get colored crystals. It's simple, safe, and fun.

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.

The Mohs test is one way to determine the hardness of a rock or mineral. You can use the Mohs hardness to help identify an unknown specimen. Here's how you can do the test yourself.

Ball point pen ink is not a something that you can usually remove with simple soap and water, but there is an easy and inexpensive way to remove pen ink from surfaces or clothing.

Rust stains can be a challenge to remove because the stain consists of tiny iron oxide particles, plus some treatments actually set the stain rather than remove it. Use a little chemistry know-how to successfully remove a rust stain.

Have you ever wondered how you could purify seawater to drink it or how you could separate salt from water in saltwater? It's really very simple.

Baking powder and baking soda both are leavening agents, which means they help baked goods to rise. They are not the same chemical, but you can substitute one for another in recipes. Here's how.

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!

Learn about the chemistry behind magic rocks and make your own chemical crystal garden.

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.

Learn about the different materials used as pencil erasers and how they work.

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.

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.

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.

Learn about how safety matches work and why they are considered 'safe'.

This article discusses bronzers, self-tanning lotions and sprays, tanning accelerators, and pills. Learn how these products work and find out why tans fade.

You blow them out, but these candles re-light themselves. Magic? No, it's simple chemistry!

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.

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.

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.

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.

Fluoride is the fluorine ion added to toothpaste and dental rinse to help protect your teeth from cavities. Here's how fluoride works.

Learn the chemistry behind how hair detangler works and get recipes to make your own homemade hair detangler.

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.

Popcorn pops because each popcorn kernel is special. Here's a look at what makes popcorn different from other seeds and how popcorn pops.

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.

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.

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.

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.

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.

Moonshine is a liquor made from fermented corn. Learn about distillation, condensation, and how this alcoholic beverage is made.

You've probably heard that trees produce oxygen, but have you ever wondered just how much oxygen one tree makes? The amount of oxygen produced by a tree depends on several factors, but here are some typical calculations.

If civilization ended right now, could I still make beer? Learn about how beer is brewed and what is required to make this popular alcoholic beverage.

Heavy water contains deuterium, an isotope of hydrogen with a proton and a neutron for each deuterium atom. Is this a radioactive isotope? Is heavy water radioactive?

Learn about pigment biochemistry and find out whether your goldfish will turn white if you leave it in the dark long enough.

Learn about transmutation, the holy grail of alchemy. Can one chemical be changed into another? Is it worth the effort?

Is it safe to use your kitchen glassware and utensils for chemistry experiments? Here's a look at some of the risks involved in using your dishes for chemistry.

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!

Have you ever wondered whether there really is such a chemical as a pool urine detector or pool urine indicator dye? Such a dye supposedly clouds the water or produces a color when someone urinates in a swimming pool. Does a urine indicator really exist?

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.

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.

Are you looking for examples of endothermic reactions for homework or to set up a demonstration? Here's a list of several heat-absorbing or endothermic chemical reactions and processes.

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.

Chemistry isn't just for chemists! Here's a nice long list of chemistry-related careers, along with a discussion on how your degree impacts your employment options.

Are you searching for something fun and educational to do that suitable for kids? Here are some great chemistry activities and projects to get you started. They are safe and use easy-to-find materials.

Do you know the chemical composition of the human body? Here's the list of elements, given in percentage according to weight.

Some common everyday chemicals last indefinitely, but others have a shelf life. This is a table of expiration dates for several household chemicals.

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 corresponding element names.

This is a list of common food additives and a description of their uses.

Find out what it means when wine has wine legs or tears of wine.

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?

Dead bodies are sometimes referred to as 'stiffs' for a reason! Learn what rigor mortis is and find out why it happens.

You probably know what elemental carbon looks like (think diamond or graphite), but you might not know what indium or cadmium look like. Here's a collection of photographs of the elements to help you out.

Find out what elements are in the human body and what these elements do.

A black light is fun for more than making retro posters glow! See examples of common materials that glow or fluoresce under a black light.

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.

Silica gel beads are found in those little packets accompanying shoes, clothing and some snacks. The packets contain round or granular bits of silica, which is called a gel but is really a solid. The containers typically carry dire "Do Not Eat" and "Keep Away from Children" warnings. So, what happens if you eat silica?

Labs have lists of chemicals that don't go together, but it isn't as easy to avoid dangerous mixtures with home chemicals because they aren't pure substances. Here's some help. Be safe and don't mix these common household chemicals.

Are you wondering what makes a chemical a chemical? Here's the answer to this frequently asked chemistry question.

Get the definition for a crystal and learn about some common types of crystals.

Find out what a heavy metal is and get examples of heavy metals.

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.

Learn what a neutron bomb is, how it works, and about a neutron bomb's strategic uses.

Absinthe has been enjoying a resurgence in popularity, as countries lift the ban on making the green wormwood and anise-flavored spirit. Learn about the history of the liqueur, why it was banned, a bit about its chemistry, how to make absinthe, and how to drink it.

Learn about absolute zero and the Kelvin and Celsius temperature scales.

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.

Learn what a bleach is, get examples of different types, and find out how bleach works.

Carnauba wax is an ingredient in many foods and household products. Here's a look at what carnauba wax is made of and the properties that make it such as useful chemical.

Here are long and short answers to this Frequently Asked Question.

Learn what crystal meth is, why people take crystal meth, how it's made, and what risks are associated with using methamphetamine.

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.

Do you know what dry ice is? Learn about dry ice and find fun projects that use dry ice.

Find out what Earth Day is all about, when it is, and how it started.

Are you confused about the difference between fluoride and fluorine or simply want to know what fluoride is? Here's the answer to this common chemistry question.

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.

Learn about natural and induced radioactivity and alpha, beta, and gamma radiation.

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...

This handy technique is used to desalinate seawater and purify bottled water. Find out how it works!

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.

Sterling silver is a popular metal for jewelry, silverware and decorations. Here is a look at the chemical composition of sterling silver.

Learn about chemical composition of the Earth's air. Percentages of the most common compounds are given, according to volume.

The coastal dead zone makes news headlines from time to time because it's implicated in fish death and may be a consequence of global warming and pollution. Do you know what the dead zone is?

Learn to distinguish between ionic and covalent bonds, and determine whether a bond will be polar or nonpolar.

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 freezing point of water or the melting point of water? Are the freezing point and melting point the same? Are there any factors that affect the freezing point of water? Here's a look at the answers to these common questions.

Learn what the greenhouse effect is and how it is related to climate.

I'll give you a hint: it isn't styrofoam! The world's lightest solid resembles a sort of solid smoke, with a density of only 19 grams per liter.

The elemental composition of the universe and the earth's crust are very different! How different? Take a look...

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?

How poisonous something is depends a lot on how it's administered and a several other factors, but this list will give you a general look at some of the most toxic substances known to man.

The Nobel Prize medal looks like gold, but what is it really made of? Here's the answer to this common question about the composition of the Nobel Prize medal.

Here's a table of the pH of several common chemicals. You can use the list to set up color ranges for pH indicators or simply to learn more about acids and bases.

Your stomach produces hydrochloric acid, so you would expect it to be acidic. Do you know just how low your stomach pH gets or whether the pH is constant? Here's a look at the chemistry of stomach pH.

Science fair and research projects apply the scientific method. Here's an informal explanation of the scientific method and how it is used.

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 or flame? Is it a liquid, solid, or gas? Learn the answer to this question and get information about the chemistry of fire.

Do you know what the strongest acid is? I'll give you a hint. It's not hydrochloric acid nor is it sulfuric acid.

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.

The thermite reaction is a highly exothermic reaction in which metal essentially burns. The thermite reaction has practical applications, such as for welding, plus it makes for a memorable chemistry demonstration. Here's how you can perform the thermite reaction, safely.

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.

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.

The most venomous insect isn't some rare, exotic rain forest creature. You may have them in your own yard. Can you name guess what it is?

You probably know that lead is toxic, but do you know what makes it poisonous? Here's an explanation of what lead does in your body that makes it such a health hazard.

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!

At what temperature does water boil? What determines the boiling point of water? Here's the answer to this common question.

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.

Learn about the chemistry of combustion.

Alphabetical list of the chemical elements named after people.

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.

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.

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.

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?

Here's a question and answer from the About Chemistry forum.

Batteries don't work equally well in hot weather and cold weather. Learn about the effect of temperature on battery performance.

Learn why clothes wrinkle and how permanent press fabrics work. It's a matter of polymer chemistry and chemical bonding.

Learn why apples, pears, bananas, potatoes, and other fruits and vegetables turn brown when they are cut or damaged.

Find out why leaves change color in the fall. Learn about the different pigments found in leaves and how bright autumn foliage is produced.

Find out why you cry when you cut onions and how you can keep it from happening.

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.

Have you ever had a ring turn your finger green or wondered why some people say rings turn their fingers green? The reason this happens is because of the metal content of the ring. Here's a look at what's happening.

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.

Learn about hydrogen bonding and density to understand why ice floats on water.

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.

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.

Do you think it's the chlorine in the swimming pool that turns blonde hair green? Guess again.

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.

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.

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.

Have you ever wondered why lb is used as the symbol for the pounds unit? Here's the answer to the question.

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.

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.

Why do you add salt to boiling water? There are a couple of answers to this common cooking question. Here's a look at the reason for salting water.

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.

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.

Usually when you see shark teeth they are black, yet teeth in living sharks are white. Here's the explanation behind why shark's teeth turn black.

Do you think a glass of water would freeze into a solid or boil into a gas if you exposed it to space? Here's the answer to the question and an explanation of what's happening.