What are the highly reactive elements in the periodic table?

The answer to you question, what are the highly reactive elements in the periodic table? is, Studies show the most highly reactive element in the periodic table is, Fluorine.

( However Cesium, Zinc, Copper, and Aluminum are known to be other strong elements too)

the old alchemists made significant contributions to science even though there starting premises were off a bit. their conclusions after failure would steer them into better directions for investigation. science is no more than close observation and the initial mistakes result in rethinking and retrying experiments.