Task: Question Answering
Input (English): Background Paragraph: The ionization energies of the representative elements generally decrease from top to bottom within a group. This trend is explained by the increase in size of the atoms within a group. The valence electron that is being removed is further from the nucleus in the case of a larger atom. The attractive force between the valence electron and the nucleus weakens as the distance between them increases and as the shielding effect increases, resulting in a lower ionization energy for the larger atoms within a group. Although the nucl. 
Story: Jeremy is studying the periodic table in preparation for a chemistry test next week. Today he is focusing on the elements that all belong to the alkali metals group. He is especially focused on learning about lithium, which is at the top of the group, and cesium, which is at the bottom of the alkali metals group. 
Question: Which element is smaller?
Output (English): lithium.