Author Archives: Anne Helmenstine

Cool Electroactive Slime That Reacts to Styrofoam

Electroactive slime is a opaque slime that reacts to static electricity. (Josh Hallett)

Electroactive slime is a opaque slime that reacts to static electricity. (Josh Hallett)

This recipe makes cool, non-toxic slime that appears to have a life of its own! It’s electroactive slime, so it reacts when it’s close to electrically charged objects. Rub a piece of polystyrene foam or a balloon on your hair or a wall to charge it and observe how the slime reacts.

Difficulty: Average

Time Required: 30 minutes

Electroactive Slime Materials

  • 3/4 c cornstarch (175 mL)
  • 2 c vegetable oil (475 mL)
  • glass or tumbler
  • refrigerator
  • 1x6x6 inch (25x150x150 mm) styrofoam

How To Make Electroactive Slime

  1. Mix the cornstarch and vegetable oil together in the glass.
  2. Refrigerate the slime mixture until it is chilled.
  3. Remove from the refrigerator and stir (separation is normal).
  4. Allow the mixture to warm enough so that it can flow.
  5. Take a block of styrofoam and charge it by rubbing it on hair, wool, or a cat.
  6. Tip the container of slime (which should flow slowly). Place the charged styrofoam about an inch (2 cm) from the flowing slime. It should stop flowing and seem to gel!
  7. If you wiggle the charged styrofoam the slime may follow or pieces of it may even break off.
  8. When the styrofoam is removed the slime will continue to flow.
  9. After use, refrigerate slime in a sealed container.

Be sure to try other slime recipes, too!

See Electroactive Slime in Action

Here’s a variation of the recipe that shows how the slime reacts with static electricity. If she had refrigerated her slime, it would be more “slimy”. The slime has a life of its own whether it’s chilled or not:

Super Easy Soap Slime Recipe

Use translucent glycerin soap to make soap slime you can see through. (darwin Bell)

Use translucent glycerin soap to make soap slime you can see through. (darwin Bell)

Soap slime is an easy-to-make type of slime that is fun to play with and makes clean-up fun. Here’s how you make it.

Soap Slime Materials

  • leftover pieces from bars of soap (or you can use a whole bar)
  • water
  • jar

Make Soap Slime

You’ve probably made soap slime accidentally by allowing soap to get wet and stay wet in the bathtub or shower. Here’s how you make soap slime, on purpose:

  1. Place the soap pieces in a jar.
  2. Cover the soap with water.
  3. Let the jar sit for a day or two. You’ve got slime!

You can play with the slime or you can use it during bath time like you would ordinary soap. The soap slime with rinse away with water. Soap isn’t edible, so don’t eat this slime either. Also keep it out of your eyes. If you get some soap slime in your eyes, immediately rinse it out with water. Otherwise, have good clean fun!

Make Dish Soap Slime

Another cool type of soap slime to make uses dish soap. The ingredients for this slime are:

  • liquid dish soap (choose the color you want the slime to be)
  • glitter
  • clear non-toxic glue (PVA or polyvinyl alcohol school glue)
  • salt water or saline solution (although you’ll get better results using borax in water)

Food That Glows in Black Light

Bananas are one of the foods that glow under black light. Only the margin of the spots glows. (endolith)

Bananas are one of the foods that glow under black light. Only the margin of the spots glows. (endolith)

Do you want food that glows in the dark? With the exception of certain types of phosphorescent fungi, edibles don’t tend to glow. However, there is some food that glows under a black light. The black light emits ultraviolet radiation, which excites atoms and causes them to release fluorescent light. Fluorescence is a fast process, so food only glows when the black light is on.

Here is a list of foods that glow and the color of the light that is produced. Tonic water glows the brightest. You can use it in place of water in certain recipes to make foods light up. Try it in white frosting, gelatin, and drinks. You can also add a bright glow to food by mixing in vitamin B2.

  • tonic water (bright blue because of the quinine that is an ingredient)
  • cooking oil (yellow to greenish-yellow)
  • olive oil (orange)
  • eggs (shell is dark violet-red, egg white is bright pale yellow)
  • honey (golden yellow)
  • pineapple (vivid blue fruit, mostly reflected light, outside doesn’t glow)
  • ketchup (yellow – not bright)
  • milk (pale yellow)
  • vanilla ice cream (yellow)
  • yogurt (yellow for vanilla, possibly pink for flavored)
  • banana (blue ring around spots, some color if you cut the banana)
  • sliced lettuce or other greens (dull red from the chlorophyll)
  • sliced peppers (dull red)
  • sliced squash (yellow)
  • some energy drinks (if they have enough B vitamins)

Foods That Reflect Black Light

Most white foods (except for egg whites) don’t glow or fluoresce under black light, but they do reflect back the light so they appear bright blue or purple. Examples of reflective foods include:

  • marshmallows
  • white bread
  • pasta
  • rice
  • potato chips
  • tortilla chips

If a food doesn’t glow, consider serving it on a white doily or fluorescent plastic plate. Fluorescent plastic cups are available in many colors. Most clear plastic has a blue glowing edge under black light. You can also decorate using glow sticks. Just make sure they stay sealed!

See Glowing Food in Action

Take a look at people’s reactions to glowing food. As you might guess, adding vitamins or tonic water to food can affect the flavor. Food usually glows green or blue, which might not seem that appetizing. It’s fun though!

What Is Casein? Casein Definition and Chemistry

The word casein comes from the Latin name for cheese. (Andrew Blight)

The word casein comes from the Latin name for cheese. (Andrew Blight)

What Is Casein?

Casein is the name given to a group of related proteins found in mammalian milk. The word “casein” comes from the Latin word caseus, which means “cheese”, which makes sense since casein is one of the main chemical substances in cheese. Cheese is made by coagulating casein, typically by acidifying milk and adding the enzyme rennet to coagulate protein. Casein is also used as binder to make safety matches, as a food additive (protein supplement), to make a quick-drying water-soluble paint, for glue and plastics, and to remineralize tooth enamel.

Casein makes up 80% of the proteins found in cow’s milk and 20%-45% of the proteins in human milk. These proteins are all phosphoproteins, which contain a high number of proline residues (an amino acid) and no disulfide bridges. The protein is poorly soluble in water, found in milk as a suspension of particles that are termed “casein micelles”. The micelles are considered colloidal particles.

Casein Safety and Health Concerns

A small percentage of people are allergic to casein and should avoid it, but most of the negative press the protein receives relating to health is unfounded. Research into a suspected link between milk consumption and cancer has shown casein cannot be identified as a causative chemical. Early studies linking chronic diseases and the A1 or A2 beta casein genetic variants have not been substantiated by modern research.

How Urine Color Works (and How to Change It)

Tired of the normal yellow urine color? There are safe ways to change it. (Knowtex)

Tired of the normal yellow urine color? There are safe ways to change it. (Knowtex)

Have you ever wanted to color your urine or wondered how urine color works? Here’s a little applied color chemistry for your entertainment and experimentation pleasure:

A Rainbow of Urine Color

Violet – Violet or purple urine is not a natural color. You can temporarily tint urine this color if you ingest foods that produce red urine and those that turn it blue. For example, you could combine beets with methylene blue.

Blue – Methylene blue is a dye that will turn your urine blue or greenish-blue. It can also color the whites of your eyes blue. The coloration of both urine and eyes is reversible. At one time, methylene blue was considered to be an effective malaria treatment. Methylene blue considered to be reasonably safe to eat, though you should be aware some people are allergic to it. Food coloring may turn your urine blue. A rare, inherited disease known as porphyria can cause blue urine. King George III’s blue urine may have been attributable to porphyria.

Green Urine from Propofol

Green Urine from Propofol

Green – Asparagus will turn urine green and also will give it a very strong odor (although not everyone can smell it. Food coloring can turn your urine green, as can certain medications. For example, the sedative propofol can produce a green tint. The allergy and asthma drug promethazine can produce blue or green urine.

Yellow – Yellow is the normal urine color. The color comes from urobilin, which is a yellow pigment resulting from the breakdown of the heme from old red blood cells. You can get bright yellow to orange urine from excessive intake of certain B vitamins. Vitamin B2 is the usual culprit. The bright color is commonly seen in urine after drinking one too many energy drinks (which are often vitamin-fortified).

Amber – Dark golden urine often results from dehydration (not drinking enough water). A very dark color might indicate the presence of bile in urine, which is symptomatic of a medical condition. If you really want to obtain this color on purpose, B vitamins are your best bet.

Orange – Eating rhubarb or senna can turn your urine orange. Senna is a dangerous herb to mess with. Stick with rhubarb. Cook the rhubarb first, since the raw plant is toxic. The drugs rifampin and phenazopyridine can color urine orange.

Red – Eating beets or blackberries can turn your urine red. Although they are orange, carrots can also turn urine reddish. Discoloration of urine due to beets actually has a name: beeturia. Blood in urine tinges it pink and is called hematuria. Any of a variety of medical conditions can cause it.

Pink Urine Color from Eating Beet Roots (Jmarchn)

Pink Urine Color from Eating Beet Roots (Jmarchn)

Pink – Pink is a safe urine color to achieve. Pink can result from a urinary tract infection or from eating smaller quantities of beets or blackberries.

Brown – Brown urine results from a kidney dysfunction (bad), jaundice (bad), rhabdomyolysis (which you can get from too much exercise), Gilbert’s syndrome, or from an overdose of the herb Goldenseal (also not good). You should probably avoid coloring your urine brown on purpose.

Black – Black is not a desirable color for urine. I’m unaware of any chemical you can take to safely get this color. It can result from Blackwater Fever, which is associated with malaria. The disease turns urine black because it kills so many red blood cells they can’t get filtered out. If blackwater fever has progressed to this stage, it’s usually fatal. Melanoma may produce black urine (clinically called melanuria). A condition called non-melanin acute intermittent porphyria can also produce black urine.

Milky or Cloudy – If urine is cloudy, it’s due to the presence of blood, protein, mucous, pus, or calcium phosphate crystallization. This often indicates an infection or disease. It’s not an effect you can get safely, as far as I know.

Clear – Clear urine is a sign of overhydration. All it takes to achieve clear urine is to drink plenty of water. Don’t go overboard, since even too much water can be bad for you.

If you decide to color your urine, be sure to use common sense. Urine color changes from foods are fairly safe, but be careful not to over-do dyes or hydration/dehydration. If you have colored urine, please don’t attempt to self-diagnose a medical condition. See a professional if you’re concerned.

Space Periodic Table Poster – 2017 Periodic Tables with 118 Elements

The space periodic table poster is our latest favorite type of table to make. Basically, we take one of our best tables and place it on a space background. Some of the images are public domain photographs taken by the Hubble telescope. Others are generated using Photoshop. Most of these are huge tables intended for posters that are too big to offer as printable tables.

Here’s a collection of periodic table posters that feature all 118 elements (for 2017) and space theme backgrounds.

Orion Nebula Periodic Table

This is a 2017 periodic table with all 118 elements. The element tiles are semi-transparent, set against a Hubble photograph of a portion of the Orion nebula. This table is only available on Redbubble because its filesize is huge. It’s on big periodic table posters, prints, and other products.

Orion Nebula Periodic Table

Orion Nebula Periodic Table

Veil Nebula Periodic Table

This table features the Veil nebula, which is also known as the Witch’s Broom nebula. The periodic table is a solid color, set against a space background. Like the Orion nebula table, we’re only offering this one on Redbubble.

Veil Nebula Periodic Table

Veil Nebula Periodic Table

Star and Nebula Periodic Table

This colorful table is set against a huge Hubble composite photograph of the Carina nebula. It’s available on Redbubble, plus you can also print it yourself. The printable is poster-sized.

Hubble Nebula Periodic Table

Hubble Nebula Periodic Table

Galaxy Periodic Table

This is a black periodic table against a photo of a spiral galaxy. The full image is featured on a periodic table poster, with a zoomed-in view on coffee mugs, clocks, and such. The galaxy background is an actual photograph.

Spiral Galaxy Periodic Table

Spiral Galaxy Periodic Table

Starfield Space Periodic Table

The element tiles are round, with a simple starfield or space background behind the periodic table. This space background was made, not photographed.

Starfield Periodic Table

Starfield Periodic Table

Original Space Periodic Table Poster

The first periodic table we offered with a space theme is this one. It doesn’t offer all 118 elements, but it is available as a printable you can download here on Science Notes or you can get it on assorted products at our Redbubble store.

Space Periodic Table

Space Periodic Table

If you have a request for a type of table you’d like to see, please let us know. We’ll add new space periodic table posters to this page as they are created.

10 Platinum Facts

Platinum is a dense, grayish-white transition metal. These crystals of pure platinum were grown by gas phase transport. (Periodictableru)

Platinum is a dense, grayish-white transition metal. These crystals of pure platinum were grown by gas phase transport. (Periodictableru)

Platinum is a highly prized white metal. Here are 10 interesting facts about this element:

  1. The name for the element, platinum, comes from the Spanish word, platina, which means “little silver”.
  2. Because platinum exists in pure native form, it has been known to mankind for a very long time. There is evidence that platinum was known to the pre-Columbian natives.
  3. Platinum does not oxidize at any temperature and is unaffected by most acids. Its resistance to corrosion makes it a good choice for jewelry and to make mass standards.
  4. Platinum is an important catalyst for chemical reactions, such as petroleum cracking, for catalytic converters in vehicles, and for converting methyl alcohol into formaldehde. The element can absorb considerable volumes of hydrogen.
  5. Platinum is considered non-toxic. It is safe for use in jewelry, is used in dental crowns, and has value as an anti-tumor agent.
  6. Like gold and silver, platinum is considered a precious metal. It is used in currency and investment.
  7. The percentage of platinum found in meteorites and Moon rocks is higher than the percentage found on Earth.
  8. Platinum is a rare metal. The pure element may be found in certain alluvial deposits. The element may be extracted during the refining of copper-nickel ores.
  9. Platinum alloyed with cobalt can be used to make strong permanent magnets.
  10. Platinum displays many properties of metals. It is silver-gray in color, shiny, ductile, malleable, and dense.