Materials and Change

4th and 5th Class

September 2024

The children in 4th and 5th class enjoyed a science experiment where they were growing their own crystals.

The children were divided into groups and they first had to prepare the salt solution:

• They began by filling a clear jar with very hot water, this was done with the help of their teacher.
• Gradually, they added salt to the water. They added enough salt so that the water became fully saturated.
• Then, they added some food colouring.
• To prepare the string; they tied a piece of string around a lollipop stick and placed the stick across the rim of the jar so that the string hangs into the solution.
• The children have been observing the crystals for the past few weeks and have noticed their own crystals growing!!

The children learned that, as the hot water cools and evaporates, it can no longer hold as much dissolved salt. The excess salt starts to come out of the solution, forming solid crystals. These crystals continue to grow as more water evaporates, leaving behind the salt in its natural crystalline form.