On Thursday it was science time again in our Montessori Preschool! The Kindergarteners spent time exploring the concepts of absorption and evaporation using water jelly crystals. During a morning session, they used their 4 senses(never taste the data!) to examine the crystals. They found they were small, hard, rough, white, odorless, and didn’t make any noise. They looked like tiny rocks.
Next, the crystals were scooped into containers filled with both plain and colored water. They also looked at some other crystals. These were tiny, transparent spheres. These were added to one cup of water in baggies. Then it was time to wait and observe.
The Kindergarteners noticed during the morning that the crystals were growing bigger and changing colors. The water in the containers was disappearing! After lunch, they had the opportunity for some hands-on investigation. The crystals were cold, wet, big and felt like Jello. They wiggled! When split open, the color was inside too. The crystals had hydrated by absorbing the water in the cups.
When the Kindergarteners checked the baggies, the crystal spheres seemed to have disappeared. But no—when they put a hand inside the bag, the crystals were still there. The crystals had absorbed so much water that they were camouflaged! The same thing had happened to the crystal in a test tube—a ghost crystal!
What happened to the crystals after the weekend? The crystals placed into test tubes made rainbows! The crystals left on Petri dishes dehydrated. The water evaporated in our warm classrooms, leaving small, hard, rough crystals that were still yellow, red and green. However, the crystals in the covered Petri dishes did remain hydrated. The Kindergarteners learned more about water absorption and evaporation experimenting with the water jelly crystals. Now they are planning to test other materials to find out which ones absorb water and which do not.