How would I find the most reactive element on this periodic table?

Question

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Answer 1

Lithium will be the most reactive out of those options.

Reactivity has to do with electron energy levels, and the stability of the electrons at the outermost energy level.

Below are some links to electron energy levels, atomic orbitals, and the Pauli Exclusion Principle, which define electron position in reference to the nucleus. This is rather heavy material, but hopefully the diagrams on these pages, in conjunction with your textbook, can show you how electrons are organized about the nucleus and better describe how they relate to element reactivity.

Answer 2

The closer to the left or right you go, and the higher on the table you go, the more reactive. Lithium is the most reactive.