Chemistry? What exactly is chemistry?

This question will be set to students in class 4.
As in medieval alchemy, our students will also observe and experiment.
Our students will learn that substances can exist in different states of aggregation.
When can gas freeze? Is that possible?
Based on the weekly project lesson, the students will carry out experiments on the 4 elements and prepare the first experimental protocols in preparation for the scientific investigation.
The first experiment will be on the subject of water.
In order not to betray too much at this point, here is just a hint: “lava lamp”.