Answer:
Potassium (k)
Explanation:
Potassium is so reactiev that it wont even be found naturally in nature, it legit racts with almost anything and doesn't take almost anything at all to start a reaction. COmpared to the other Potassium is easily number 1
That would be Biochemistry. as that is th study of chemical changes and processes in living organisms
Manipulated Variable:The speed working on maths problems
Responding Variable: The group that use¬ using a calculator
Controlled Variable:The same maths quetions