Washing Soda Stalactite-Cave Pillar
If you've ever ventured into a naturally formed cave, you probably saw pillars stretching from the ceiling to the floor. They're called stalactites and they take hundreds and thousands of years to form as precipitation drips from down from the cave's ceiling. In the Washing Soda Stalactite experiment, you'll cut the stalactite formation process down to just a couple of days.
- Washing soda
- Hot water
- Large washcloth
- Small plate
- Two beakers or glasses
- Start by filling two beakers with hot water. Leave about an inch at the top of your beakers to avoid spilling the water during the rest of the experiment.
- Add approximately 1/2 cup of washing soda to each beaker and stir both beakers until all of the washing soda is dissolved.
- Fold the washcloth in half, making a triangle, and roll it up tightly.
- Use scissors to cut three lengths of string and use the string to tie the washcloth on both ends and in the middle. Once the washcloth is tied, trim the excess string off of your knots.
- Put each end of the washcloth into its own beaker. Make sure that the ends of the rag touch the bottoms of the beakers.
- Pull the center of the rag down so that it hangs towards the table.
- Put the plate under the center of the rag and let it sit for three to five days.
- Check back during the waiting period to see the progress and watch as the stalactite forms. After the waiting period is up, you should have a pillar that stretches all the way from the washcloth to the plate!
How Does It Work?
- Wonderful Review by Casey
This is a great experiment for my secondgrader! We will definately be doing this soon! Great for Arkansas history...have to branch a little history in with the science as well right ;-)
(Posted on April 23, 2012)
- Washing soda stalaite cave pillar Review by Lauren
this is a fun project to do ! Its simple and doesn't need to take a whole month to do it,but just days it will be done!
(Posted on November 12, 2012)
- Great concept but... Review by Erin
It would have really been helpful to know how much water you start with on this. I tried to "eyeball" it based on the pictures, but I definitely did not have enough water. We got a stalactite, but before it could create the column, because the water was so saturated with the washing soda, it crystallized solid into the glasses and the growth stopped after about a day. I will try with larger glasses, but it was disappointing for my Pre-K (and, of course, her mom) doing her first science experiment/demo for school.
(Posted on February 24, 2013)