A fun experiment that you could try over the Spring could be 'dancing coloured rice'.
For this experiment you would need a vase of any shape, but I have found a largish transparent one works best. If you don’t have a vase, you could use mason jars or ordinary glasses. You would also need a bottle of clear lemonade or sparkling water and some coloured rice, (though jingle bells/beads/popcorn would work just as well) which could be created by soaking dry rice in small containers of different coloured paint, overnight.
Ask your preschoolers or Key Stage 1 children to gather around. They could either sit around the table or stand. I always find being flexible with seating arrangements makes for more enjoyable experiences for children and their care givers.
Once they are settled you could maybe start by asking them how they think coloured rice could dance or move on their own. Listen to what the children have to say.
Put the vase or mason jars on the table in front of the children, then pour in the clear lemonade or sparkling water to the top. Give each child a small container of dry coloured rice, then ask them to put the rice into the vase/jar/jars. Ask them to watch what happens to the grains of rice.
Ask them what they think is happening to the coloured rice. Listen to what the children have to say. Then explain to them that the carbon dioxide bubbles lift the grains of rice up and once they hit the surface they pop, and the grains of rice gently drop down again.