For this Year 6 science project you will need:
What to do:
- Fill the jars with hot
water.
- Add as much baking soda to each jar as will
dissolve.
- Mix well to dissolve the baking soda.
- Dip one end
of the wool in each jar, making sure the ends are weighed down by the
paperclips.
- Place the saucer or plate between the jars.
- Let
the thread hang between the jars, over the saucer.
- Leave for 2-3
weeks.
What happens:
A white stalactite grows down from
the wool and a stalagmite grows up from the saucer.
Why It
Happens:
The baking soda mix is carried up through the wool. This is
called capillary action. The mix then drips onto the saucer. Over the
days, the dripping water evaporates, leaving a little of the baking soda
behind. These bits of baking soda make a tiny stalactite and stalagmite.
After a few months, these will join to make a single column like the ones
you might see in a cave.