Tag Archives: chemistry projects

Slime Recipes

The most popular of the slime recipes is the one using borax and glue.

The most popular of the slime recipes is the one using borax and glue.

Slime is a classic science project. There are lots of different ways to make it, so you’re sure to have ingredients to make it. Here’s a collection of easy slime recipes to try:

Classic White Glue and Borax Slime Recipe

Let’s start with the go-to slime recipe, made using white school glue and borax.

  • borax powder (e.g., 20 Mule Team borax sold as a laundry booster)
  • water
  • 4 ounce (120 ml) non-toxic white glue (e.g., Elmer’s school glue)
  • food coloring (optional)
  1. In one container, stir together 4 ounces (1/2 cup or 120 ml) glue and 1/2 cup water.
  2. Add a few drops of food coloring, if you want colored slime. If you don’t add coloring, your slime will be opaque white.
  3. In a separate container, mix together 1 teaspoon (5 ml) borax powder and 1 cup (240 ml) water.
  4. It’s easy to make the slime. Simply mix the glue solution and the borax solution together!
  5. Work the slime with your hands. You can discard any leftover water.

Goo or Oobleck Slime Recipe

Oobleck is a type of slime that behaves as a viscoelastic or non-Newtonian fluid. (David Mulder)

Oobleck is a type of slime that behaves as a viscoelastic or non-Newtonian fluid. (David Mulder)

Goo or oobleck is a non-sticky opaque slime that is an example of a non-Newtonian fluid. This means it acts differently according to external conditions. This slime flows like a liquid, but if you squeeze it hard or punch it, it feels solid. All versions of this slime are non-toxic and safe even for very young children. There are actually a few different ways to make goo or oobleck. The simplest is to mix together corn starch and water or corn starch and vegetable oil. If you have the materials, using liquid starch instead of powdered corn starch and white glue instead of water or oil makes a nice slime:

  • 1/2 cup white glue
  • 1 cup liquid starch
  • food coloring (optional)

Mix the ingredients together in a bowl or squish them together in a plastic bag.

Glow in the Dark Slime Recipes

Glowing Slime

Glowing Slime

You can turn any slime into glow in the dark slime by adding a phosphorescent powder or by replacing glue in a recipe with glow in the dark glue. Make slime that glows under a black light by adding highlighter ink instead of food coloring.

Note: Most phosphorescent powders are destroyed by contact with water! Your best bet is to use a powder made for mixing into acrylic (water-based) paint or a pre-mixed liquid solution, like a paint or a glue.

Here’s the recipe for the slime I made for this photo:

  • borax powder
  • Elmer’s™ non-toxic blue glue gel (You could use any transparent glue. Avoid white glue because it blocks the “glow.”)
  • Glow-Away™ washable paint (I got this at Michael’s craft store, but any glow-in-the-dark washable paint will work.)
  • water
  1. Mix together 1/3 cup glue and 1 cup water.
  2. Stir or whisk in paint to achieve the desired glow. I used half a tube of glow paint. I had charged the paint under a black light (could use bright sunlight), so I would know how bright it would be in the slime.
  3. In a second bowl, stir borax into half a cup of hot water until it stops dissolving. This gives you a saturated solution without having to measure the borax. If you feel like measuring, add 1-2 teaspoons of borax.
  4. To make the slime, mix together 1/3 cup of the borax solution with 1 cup of the glue/glow mixture.
  5. Charge the slime by exposing it to bright light for a few minutes or a black light for a few seconds. It will now glow in the dark!

Slime Storage and Clean-Up

  • Store any type of slime in a sealed container when you’re not using it.
  • You can keep mold and other nastiness away from the slime by refrigerating it between uses.
  • Clean up slime messes using warm, soapy water.
  • If you used food coloring, remember it may stain fabric and your hands.

Need more slime recipes? My full recipe collection at About.com Chemistry contains many more!

How To Make Homemade Shampoo

These are bars of homemade shampoo. You can add water to make liquid shampoo, if preferred. (Kim, Flickr)

These are bars of homemade shampoo. You can add water to make liquid shampoo, if preferred. (Kim, Flickr)

You can apply chemistry to make homemade shampoo. One of the biggest reasons to make your own shampoo is to avoid unwanted, potentially toxic chemicals. Another reason you might want to make your own shampoo is so you can customize the formulation for your hair’s needs and your preference for fragrance (or lack of fragrance). Here’s a recipe for a gentle vegetable-based shampoo. It’s similar to my earlier shampoo recipe except this one uses potassium hydroxide instead of lye, which produces a shampoo that lathers better and rinses more easily. Mix the shampoo in a well-ventilated room or outdoors and be sure to read all of the safety precautions on the ingredients. Readers have recommended triethanolamine or diethanolamine in place of sodium hydroxide or potassium hydroxide. Choose the formulation that works best for you.

Homemade Shampoo Ingredients

  • 2 lb 10 oz olive oil
  • 1 lb 7 oz of solid-type vegetable shortening
  • 1 lb coconut oil
  • 14.4 oz potassium hydroxide
  • 2 pints water
  • 1-1/2 oz glycerine (glycerol)
  • 1/2 oz ethanol
  • 1-1/2 oz castor oil
  • essential oils (optional), such as peppermint, rosemary, lavender, for fragrance and therapeutic properties

Let’s Make Shampoo!

  1. In a large pan, mix together the olive oil, shortening, and coconut oil.
  2. In a well-ventilated area, preferably wearing gloves and eye protection in case of accidents, mix the potassium hydroxide and water. Use a glass or enameled container. This is an exothermic reaction, so heat will be produced.
  3. Warm the oils to 95°F-98°F and allow the potassium hydroxide solution to cool to the same temperature. One of the easiest ways to accomplish this is to set both containers into a large sink or pan full of water that is at the correct temperature.
  4. When both mixtures are at the proper temperature, stir the solution into the oils. The mixture will turn opaque and may darken.
  5. When the mixture has a creamy texture, stir in the glycerine, alcohol, castor oil, and any fragrance oils or colorants.
  6. You have a couple of options here. You can pour the shampoo into soap molds and allow it to harden. To use this shampoo, either lather it with your hands and work it into your hair or else shave flakes into hot water to liquefy it.
  7. The other option is to make liquid shampoo, which involves adding more water to your shampoo mixture and bottling it.

You can make your homemade shampoo pearlescent if you add a little glycol distearate, a natural wax derived from stearic acid. The tiny wax particles reflect light, causing the effect.

Periodic Table Buttons

013 - Aluminum Button

013 – Aluminum Periodic Table Button

Periodic table element tiles are fun to arrange into different words and sentences. Print out your favorite elements and spell out whatever you choose. Our other periodic table tiles are based on the typical square shape and are popular in their own way. This set of tiles are slightly different.

Each element’s tile is a colored disk stylized to give the effect of a shiny button.

Each button is 400×400 pixels in size (5 inches in diameter), making them large enough to be seen in a classroom setting. These same buttons were used to make the Periodic Table Circle Buttons Wallpaper . You can make your own version of this table with this complete set of buttons. With this in mind, and to save you a lot of individual downloads, I have included a download link to a ZIP archive of all the elements and the element group buttons.

Periodic Table Refrigerator Magnets

Another idea for these periodic table buttons is to make refrigerator magnets.

You’ll need:

Instructions:

  1. Download your favorite element button (or all of them at once).
  2. Scale down the images by 50%. This will make them almost exactly the 2½” size needed to use the paper punch.
  3. Punch out the button using the paper punch.
  4. Place the disk inside a blank button and replace the clear cover.
  5. Cut 1″ square pieces from the magnetic sheets.
  6. Peel off the backing to expose the sticky part of the magnet and stick it to the back of the button.
  7. Enjoy your new periodic table refrigerator magnet.

Homemade Black Snake Fireworks

Black Snake Firework (Anne Helmenstine)

Black Snake Firework (Anne Helmenstine)

Black snake fireworks are small, non-exploding fireworks that you ignite to push out a growing column of black ash. While you can buy these fireworks, they are easy to make using kitchen ingredients and a fuel.

Materials

  • 4 teaspoons powdered or confectioner sugar (sucrose)
  • 1 teaspoon baking soda (sodium bicarbonate)
  • lighter fluid or rubbing alcohol
  • sand or dirt (optional)

Make Black Snake Fireworks

  1. Mix together the sugar and baking soda.
  2. Make a depression in sand or dirt, pour the mixture into the depression, and lightly cover it with a fine layer of sand. You could just use sugar and baking soda in a bowl, but it makes for a cool effect where the snake seems to push out of the ground!
  3. Dampen the soil and mixture with lighter fluid or rubbing alcohol.
  4. Light the fuel with a match or lighter. Once the sugar in the underlying mixture catches fire, the black snake will start to grow.
  5. The firework goes out on its own, but you can extinguish it with water or by covering it with dirt.

Colored Soap Bubbles

Colored Soap Bubble (brokenchopstick, Flickr)

Colored Soap Bubble (brokenchopstick, Flickr)

Clear bubbles are a lot of fun, but you can make colored soap bubbles, too. Here’s a recipe for pink or blue colored bubbles, based on disappearing ink (a type of acid-base indicator), so the bubbles won’t stain surfaces when they land.

Colored Bubble Materials

  • Liquid Dishwashing Detergent (or other detergent)
  • Water
  • or Commercial Bubble Solution
  • Sodium Hydroxide
  • Phenolphthalein
  • Thymolphthalein

Colored Bubble Instructions

  1. If you don’t have bubble solution, you can make your own by mixing 1/2 cup (500 mL) liquid dishwater detergent, 4-1/2 cups (4.5 L) water, and 4 tablespoons glycerin (60 mL).
  2. Add the sodium hydroxide and indicator to the bubble solution. For 1 liter (~4 cups) of pink bubble solution, mix about 10 grams (1-1/2 to 2 teaspoons) phenolphthalein and 2-2.5 grams sodium hydroxide (about a half teaspoon) into a liter of bubble solution. For blue bubble solution, you want 10 grams of thymolphthalein and ~2 grams sodium hydroxide. You may find it necessary to dissolve the indicator in a small amount of alcohol before mixing it with the bubble solution.
  3. If you have it, you could use pre-made indicator solution, adding the sodium hydroxide to the indicator rather than diluting with water. Just mix the indicator and sodium hydroxide with bubble solution.
  4. You’ve essentially made disappearing ink bubbles. When the bubble lands, you can make the color vanish by blowing on it or rubbing the spot (reacting the liquid with air). To make the spot disappear even more quickly, spritz a little club soda onto the area.
  5. Another option for making colored soap bubbles is to mix disappearing ink (from a toy store or magic shop) directly with bubble solution.

Colored Bubble Safety Information

  1. Please don’t drink the bubble solution! Unused bubble solution may be stored in a sealed container or disposed of by pouring it down the drain.
  2. These are bubbles intended for ‘blowing bubbles’, not for bathing.
  3. Sodium hydroxide is a strong base. Avoid direct contact with this ingredient. If you do get some on your hands, rinse them immediately with water.
  4. You could make color-change bubbles as easily as disappearing ink bubbles. Phenolphthalein and thymolphthalein change from red or blue to uncolored around pH 10.

 

Charcoal Crystal Garden

Crystal Garden (Anne Helmenstine)

Crystal Garden (Anne Helmenstine)

The charcoal crystal garden is a classic crystal-growing project. You use charcoal briquettes, cardboard or a sponge, ammonia, salt, bluing, and food coloring to grow a crystal garden. The components of the garden are not edible, so adult supervision is recommended.

Materials

  • charcoal briquettes, cardboard, or pieces of sponge or porous rock
  • water
  • table salt (sodium chloride)
  • ammonia
  • laundry bluing agent
  • food coloring
  • glass dish or shallow bowl (non metal)
  • measuring spoons
  • clean glass jar

Step-by-Step

  1. Gather your materials.
  2. Place chunks of your substrate (i.e., a cardboard scene, charcoal briquette, sponge, cork, brick, porous rock) in an even layer in the non-metal pan. You want small pieces, so you may need to (carefully) use a hammer to break the material up.
  3. Sprinkle water, preferably distilled, onto the substrate until is has been thoroughly dampened. Pour off and discard any excess water.
  4. In an empty jar, mix 3 tablespoons (45 ml) uniodized salt, 3 tablespoons (45 ml) ammonia, and 6 tablespoons (90 ml) bluing. Stir the mixture until the salt is dissolved.
  5. Pour the mixture over the substrate layer (over the scene, brick or sponge or whatever).
  6. Add and swirl a bit of water around in the empty jar to pick up the remaining chemicals and pour this liquid onto the substrate, too.
  7. Dot drops of food coloring here and there across the surface of the ‘garden’. Areas with no food coloring will be white.
  8. Sprinkle more salt (about 2 T or about 30 ml) across the surface of the ‘garden’.
  9. Allow your ‘garden’ to grow in an area where it will not be disturbed.
  10. On days 2 and 3, pour a mixture of ammonia, water, and bluing (2 tablespoons or 30 ml each) in the bottom of the pan. Try to avoid pouring liquid on the delicate growing crystals.
  11. Keep the pan in an undisturbed place, but check on it periodically. Let it grow until your are pleased with its appearance. Enjoy!

Tips for a Beautiful Charcoal Crystal Garden

  • Bluing is found in the laundry aisles of some grocery stores. If you can’t find bluing at a store near you, it is available online.
  • The crystals grow quickly for this project because the substrate (charcoal or whatever you chose) has a large surface area. Crystals start to form on the porous materials and then grow as capillary action draws more fluid up from the dish. Water evaporates on the surface, depositing solids/forming crystals, and pulling more solution up from the base of the dish.

View a Time Lapse of the Charcoal Crystal Garden Growing

Here’s a video I took of these crystals growing. You can expect to see growth within about half an hour, with a good change of appearance overnight.