This teacher did this for a preschool lesson, but it can be adapted for older kids. They could drop or open the balloons and observe what happens to the solid liquid and gas inside it. This would help identify the properties of solids, liquids and gases.
Primary level science station for magnets. "Is it magnetic?" This sorting science station is appropriate for pre-k, kindergarten, primary grades, or preschool. With younger children be careful to ensure items size isn't a choking hazard.
Buoyancy Bring a basket of loose parts, natural materials and other pieces to the water table. First ask them to guess which sink or float and then ask them to see if they were right or not.This activity is good to see how materials interact with water.
Great demonstration of how pesticides and other chemicals can easily be absorbed by vegetables.Toddler Science: Celery Experiment, Learn about Plants and How They Absorb Water in This Science Project for Kids
Fine motor activity (for indirect control of a pencil and a paint brush): Tweezing sunflower seeds, then roast or bake with a little oil, hing, black salt, as a snack offering for Krsna. ( you would probably need to grow that sunflower first!
"I bought a simple, inexpensive flashlight, took it apart, and placed it on the science shelf. Children put it back together like a puzzle through trial and error. Once they get all the pieces together correctly, the flashlight will turn on!
Put real spiderwebs on paper. preserve a spiderweb on paper to explore/look at. or put the black paper behind it so it can be seen in detail and then take a picture so you don't have to destroy the spider's web.