Final answer:
Iron (Fe) is considered the most stable and thus 'powerful' element in terms of binding energy. Cesium (Cs) has the largest atoms, and elements like rubidium (Rb) have lower ionization energies compared to others. The periodic table is continually being expanded with new superheavy elements extending past element 118.
Step-by-step explanation:
When discussing the most powerful element on the periodic table, it's important to define what 'powerful' means in a chemical context. Binding energy is often a measure of an element's stability, and in this case, iron (Fe) is the most stable element since it has the greatest binding energy for nuclei with mass numbers around 56. This means that iron gives up the most energy when it forms from component particles, and conversely, it would require the most energy to break it back down into protons and neutrons.
Other elements on the periodic table have noteworthy characteristics as well. For instance, cesium (Cs) has the biggest atoms among naturally occurring elements, reflecting its large atomic radius. Also, when considering ionization energies, rubidium (Rb) located at the bottom left of the s-block on the periodic table has the lowest first ionization energy, indicating it's easier to remove an electron from Rb than from elements with higher ionization energies.
Scientific exploration continues to extend the periodic table, with recent additions filling the seventh row up to element 118. Beyond element 118 is the hypothesized 'island of stability', where it's believed elements could exist with higher atomic numbers and potentially larger lifetimes than the extremely unstable superheavy elements currently known.