Question

who is demonstrating the experiment​

Answer 1

a demonstration, often by a teacher in a classroom, of a well-established fact. Demonstration experiments are usually not experiments in the technical sense of comparing experimental to control conditions after randomization.

Answer 2

a scientific demonstration is an explanation of a process that is illustrated through an example which services as proof or evidence of the scientific principles at work in other words are scientific demonstration allows the student to study the principles of science first hand