Experiments or Practical Activities (called pracs for short) are a critical part of school science, not (just) because they are fun, but because they form the basis of science in the world. Theories are one thing (and an important part of science) but they are dependent on experiments – without the proof that real world experiments provide, theories would be nothing more than opinions – and have no more validity for understanding the world than any number of other belief systems.
The scientific method developed in ancient Greece, but has continued through a great deal of “western” science. The basic idea behind the scientific method is that nothing is ever proven conclusively and forever. This means something different than most people interpret it to mean – not that nothing can ever be known (after all ideas like evolution are almost universally accepted amongst the scientific community), but that any theory is always subject to challenge if new information or evidence is uncovered – there is no precedence of authority or ranking. Anyone can look into a theory, and if they find evidence that would seem to challenge the prediction of a theory, present that evidence to the world and the scientific community for evaluation – and if others confirm the evidence, the theory that it challenges may be reconsidered. If the required change is significant enough, it is called a paradigm shift. The most classic example of a paradigm shift is Einstein’s update of Newtonian dynamics to take speeds approaching light into consideration.