Density is a fascinating and sometimes tricky idea to understand. This Drink of Density will help bring home the idea of density in liquids, not to mention it looks cool when your all done, it’s tasty, and it’s even good for you – what more could you ask for in a science activity!
You will need:
- Juices that have different density levels. (see below for a simple explanation of density) The density of a juice is often determined by how much sugar or fruit is in it – the more sugar or fruit, the more dense the juice is. Powdered and canned juices do not work well for this experiment since they are almost entirely water. You will have to do some experimentation to find juices that are colorful and give a nice display of density, and that’s half the fun.
- A narrow glass (the more narrow it is, the easier it is to separate the density levels)
- Eye dropper or turkey type baster.
What to do:
- Before you begin, you can guess which juices you think will be more dense and form a hypothesis of how the levels of your Drink of Density will turn out. Check the number of ingredients, the sugar content, and the water content to help you out.
- In order to display your density levels, you will need to find out which of your juices are the most and least dense. Pour one of your juices into the narrow glass to fill it about 1 inch (2.5 cm) high. Fill a dropper with another juice and slowly drop it onto the inside of the glass so that it runs down the side of the glass. Watch the juice to see if it goes below or above the juice in there. (if it simply mixes with the juice and does not go above or below, it has the same density as the juice and you will need to move on to your next juice.
- Continue experimenting with other juices to determine which juices go to the bottom (more dense) and which ones go to the top (least dense.)
- Once you have the densities determined, start over with a clean glass and use the dropper for each level to create your final Drink of Density!
Note: In case you were wondering, the juices in the photo are (top) Tropicana Pomegranate-Blueberry, (middle) Tropicana Pure Premium Orange Juice, (bottom) Nature’s Promise White Grape (33 grams of sugar in 6.75 ounces!)
How Does It Work?:
The density of liquids demonstrates the the amount of “stuff” (atoms, mass) that are present in a particular volume of the juice. In other words, if you have cup with 200ml of plain water, and a cup with 200 ml of water that has lots of sugar dissolved in it, the cup of sugar water will be heavier even though they are the same volume of liquid – the invisible sugar molecules are dispersed in the water, making it heavier (more dense.)
Amy Huntley is a former science teacher and Mom that runs a great blog where she shares activities that she has done with her family. This exploration of polymers and bouncing balls caught our eye and we were happy that Amy would share it with us. We’ve adapted it just a bit. The fun part is experimenting, and it is easy to make several of these and change up the recipe and check results. Note that this will not make a bouncy ball like you get at the grocery store, but ours bounced over a foot high and the ball has quite a unique feel to it.
You will need:
- Borax (found in laundry section)
- warm water
- corn starch
- glue (clear glue makes a see transparent ball and white glue makes an opaque ball)
- 2 small mixing cups
- a stirring stick (plastic spoon)
- food coloring (optional)
- Label one cup ‘Borax Solution’ and the other cup ‘Ball Mixture’.
- Pour 4 ounces (120ml) of warm water into the cup labeled ‘Borax Solution’ and 1 teaspoon of the borax powder into the cup. Stir the mixture to dissolve the borax.
- Pour 1 tablespoon of glue into the cup labeled ‘Ball Mixture’. Add 3-4 drops of food coloring, if desired.
- Add 1/2 teaspoon of the borax solution you just made and 1 tablespoon of cornstarch to the glue. Do not stir.
- Allow the ingredients to interact on their own for 10-15 seconds and then stir them together to fully mix.
- Once the mixture becomes impossible to stir, take it out of the cup and start molding the ball with your hands. The ball will start out sticky and messy, but will solidify as you knead it. Once the ball is less sticky, continue rolling between your hands until it is smooth and round!
“My boys loved making these “bouncy” balls. They are not super bouncy like the plastic super balls that became popular when I was a kid, but they are pretty bouncy and fun to play with. We discovered that on the carpet, they have a lot more bounce then they do on the kitchen floor. ”
These are also “temporary” bouncing balls and will lose their elasticity within a few days as they dry. Keeping your bouncy ball in a sealed bag will increase its bouncy lifespan.
The original “Super Balls” got their amazing bounce ability from compressed rubber under thousands of pounds of pressure.
How does it work?
This activity demonstrates an interesting chemical reaction, primarily between the borax and the glue. The borax acts as a “cross-linker” to the polymer molecules in the glue – basically it creates chains of molecules that stay together when you pick them up. The cornstarch helps to bind the molecules together so that they hold their shape better.
Make it an experiment
You can turn this activity into a true experiment by adjusting the amount of borax, glue, and cornstarch to get the highest bounce. You can also experiment to discover the best way to get the bouncy ball to keep its bounce over time. Have fun!
Check out Amy’s blog by clicking HERE.
Lara runs a homeschooling blog from her home in Arkansas. One day, she gathered her kids and all the materials to make slime but she did not tell them what they would be creating. Using a familiar recipe, the boys were soon measuring, mixing, stretching, and yes, even learning about types of matter and polymers. Here’s Lara’s proportions for her large batch of slime. (See link below for smaller batches and to get some information about the science of polymers)
- 1 8-ounce (240 ml) bottle of glue
- 2 cups of (480 ml) warm water, divided
- food coloring
- 1 1/2 (8 ml) teaspoons Borax powder
- bowls for mixing
Pour the whole bottle of glue into a big bowl then fill the empty bottle with 1 cup of warm water and add that to the glue. Stir it up until it thins out.Then add several drops of food coloring and mix that in.In a separate bowl mix the Borax and the second cup of warm water until the Borax dissolves.Stirring CONSTANTLY, slowly pour the Borax into the bowl of glue. Stir and stir and stir until it forms into a goopy, slimy, mass. Remember to store it in an airtight container or it will dry out.