Final answer:
To predict the element with the lowest first ionization energy for each given group, we look at their positions on the periodic table. Due to periodic trends, the lowest ionization energy typically belongs to elements that are furthest to the left and lowest in their respective groups. Thus, the elements with the lowest ionization energy for each group are At, Pb, K, Fr, and Ba respectively.
Step-by-step explanation:
The subject of this question is first ionization energy, which is a chemistry concept referring to the energy required to remove the outermost electron from a neutral atom in its gaseous state. Predicting which element has the lowest first ionization energy requires the knowledge of periodic trends. Generally, first ionization energy decreases down a group and increases across a period.
- For the group Cl, I, At - At (Astatine) will have the lowest ionization energy because it is lower on the periodic table.
- For the group Sn, Pb, Si - Pb (Lead) will have the lowest ionization energy since it is both lower and further to the right than Sn, and much lower than Si on the periodic table.
- For the group K, Ga, As - K (Potassium) has the lowest ionization energy being on the far left of the periodic table compared to Ga and As.
- For the group Fr, Ga, He - Fr (Francium) has the lowest ionization energy as it is in the bottom left corner of the periodic table.
- For the group Ba, Mg, Ca - Ba (Barium) has the lowest ionization energy being the lowest element in its group.