what is the thing that you change in an experiment so that you can study the result of the change its called?

What is the percentage by mass of silicon (si) in iron aluminum silicate (fe3al2(sio4)3)?

One of the few xenon compounds that form is cesium xenon heptafluoride (csxef7). how many moles of csxef7 can be produced from the reaction of 13.0 mol cesium fluoride with 12.5 mol xenon hexafluoride? csf(s) + xef6(s) csxef7(s)

What is the subscript for oxygen in its molecular formula