by Meredith Brustlin, CMNH Educator
- Oven safe dish - reusable or disposable aluminum
- Steel wool
- 9V battery
- Jug of water - just in case!
Instructions & Safety:
- Since this activity does produce smoke, you may want to set-up outside. Just be sure if you do this experiment outside that it is not a windy day.
- I did this experiment inside my house several times and there was not enough smoke to set off any smoke detectors! HOWEVER I had coarse grade steel wool so the circuits & smoke were far less significant. If you have FINE grade steel wool, do this experiment outside.
- If you have young scientists--do this experiment as a demonstration (“I’m going to do it, and you get to watch!”)
- If your scientists are older, they can do this experiment but make sure they are closely supervised.
- The steel wool produces sparks & fire
- The 9V battery will eventually get fairly warm to the touch.
- Pull apart your steel wool so that it is in a very thin layer
- Place the steel wool into your oven safe dish or container
- Place the battery and jug of water nearby.
- Take time at the beginning of this experiment--whether you are doing it as a demonstration or young scientists are participating--to discuss safety.
- Ask scientists what they see. Invite them to feel the steel wool. What does it feel like? Does it remind them of anything?
- Explain that today you are going to make spooky sparks by creating circuits within the steel wool.
- Use the battery to gently touch down on the steel wool---watch as sparks fly through the steel wool creating a chemical reaction!
- Keep creating circuits! Eventually you will “use up” all the steel wool and the circuits won’t work anymore. Also be conscious of the battery warming up--it’s working hard!
We are seeing a chemical reaction take place in this experiment, Anytime something burns, we are seeing a chemical reaction! This type of chemical reaction is called a combustion reaction.
You are seeing the steel wool react with oxygen and in this case it is forming iron oxide.
We were also seeing circuits at work! When both battery terminals touch the steel wool, the electrons from the battery move rapidly through the steel wool and make a complete circuit. This electrical current is heating up the wire (to ~700 degrees!) and this heat causes the iron to react with the oxygen surrounding the little strands of steel wool. This reaction is what causes the sparks (homeschoolscientist.com).
Bonus Activity: Fizzy Pumpkins
- Baking Soda
- Red & yellow food coloring
- Small piece of cardboard
- Tray or cookie sheet/pan
- Pipette or paintbrush
- Small cup of vinegar
- Make your fizzy pumpkin!
- Measure out about ½ a cup of baking soda into a bowl
- Slooooowly add water until the baking soda comes together to form a moldable paste
- Add yellow and red food coloring to make orange and mix together
- Use your hands to shape the baking soda into a ball
- Push in the piece of cardboard in the top to look like the stem of a pumpkin
- **You can either make your pumpkin immediately before doing your experiment, or make it the night/several hours before**
- If you make it right before your pumpkin will be “mushy” but still hold its shape
- If you make it hours before doing the experiment, the baking soda will dry out and become hard as a rock!
To set-up your experiment area, put the pumpkin on a plate or tray and set the cup of vinegar and pipette/paintbrush nearby.
- Invite young scientists into the experiment area
- Ask them what they see!
- If you’d like, you can tell them they can carefully touch the pumpkin with one finger and guess how it was made/what material was used to make it.
- Introduce the vinegar and pipette/paintbrush and tell young scientists to carefully drip some vinegar onto their pumpkin
- What happens?!
- Keep playing until the pumpkin turns into pumpkin mush!
This is a classic acid and base experiment. When vinegar (an acid) interacts with baking soda (a base) we get a chemical reaction. In this case we’re producing a gas (carbon dioxide) and lots of fun fizzing and bubbles!