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Tuesday, September 3, 2024

Dancing Spiders Science Experiment

If your kids love Halloween, the itsy-bitsy spider, or you're doing a bug unit at school, you'll love this super quick and easy dancing spiders science experiment. You can set it up in less than 2 mins and you'll have loads of jumping spiders dancing and floating around like magic!

jumping spiders science experiment - plastic spiders jumping up from Alka-Seltzer reaction.


DANCING SPIDER EXPERIMENT


This dancing spider experiment is a fun way to visually teach your children, or students, about both chemistry and density at the same time. The solution for the experiment includes liquids with different densities {oil and water} and the chemical reaction that occurs allows the spiders to dance through those layers.

Fun fact: jumping spiders can be found all over the world, mostly in tropical forests, and the male jumping spiders dance to impress the females during mating season. This experiment is a fun way to gracefully recreate this {with a lot less twerking}. 



Supplies needed for jumping spider science experiment.

You'll need a clear oil for this experiment in order to see the spiders jumping as clearly as possible. The cheapest clear oil I could find was baby oil {ours is 100% mineral oil}, however if you have coconut oil at home already you can also use that.

Please only use plastic jars to create this experiment to ensure that if the jar is accidentally knocked over by a child it won't break. Also make sure the lid is kept off during the experiment as the gas created will build up too much pressure if the lid is on.

JUMPING SPIDERS SCIENCE EXPERIMENT


1. Pour a small amount of water into bottom of the clear jar. The amount will vary depending on what size jar you're using, however you want the water to only fill about 10% of the jar.

2. Pour clear oil into the jar until it's 3/4 full. Again the amount of oil needed will vary depending on the size of the jar.

3. Drop spiders into the jar. They will fall down through the oil and float on top of the water layer. Don't worry if they land upside down.

Dropping plastic spiders into jar for science experiment.

4. Crush an Alka-Seltzer tablet into small pieces. The experiment works better when the tablet is already crumbled into smaller pieces as it spreads the reaction out across a bigger area making more spiders jump.

5. Drop the crushed Alka-Seltzer tablet into plastic jar. Watch the jumping begin.

jumping spiders dancing as the Alka-Seltzer tablet dissolves.

The reaction will last approximately 30 seconds as you can see in our video below. You can make the spiders start jumping and dancing again by adding another crushed Alka-Seltzer tablet to the solution. I recommend waiting until the bubbles have settled from the first reaction before performing the experiment again as this will give a much clearer view of the spiders.



How does the dancing spider experiment work?


This experiment involves both density and a chemical reaction which work together to make the spiders dance around. When you first put the oil and water into the jar, they'll split into two separate layers. The water will fall to the bottom as it's the densest liquid and the oil will float above it. This may be a bit hard to see at first as both liquids are clear, however once you drop the spiders in they'll fall through the oil layer and float on top of the water layer so you can clearly see the split between the liquids.

Once you drop the Alka-Seltzer tablet into the liquid it falls to the bottom and when it reaches the water the citric acid and baking soda will start to react. The reaction dissolves the powder and produces carbon dioxide gas which forms lots of bubbles. The bubbles are less dense then both liquids so they float to the top of the jar. The force of them rising also carries the spiders to the top of the jar. 

Once they reach the top the bubbles pop to release the gas and then the spiders will fall back down through the oil layer to settle at the top of the water again. Because the Alka-Seltzer tablet takes about 30 seconds to completely dissolve, the reaction continues occurring for this time pushing spiders up and down in a continuous pattern making them appear as if they're jumping or dancing.

Dancing spider science experiment for kids.


More Halloween science experiments for kids



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Would you like to comment?

  1. My son has been asking to do science experiments, so thank you for these ideas. I love that you've given a clear explanation of the concepts involved as well.

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