The most reactive elements among the options provided are Francium and Fluorine.
1. Francium (Fr): Francium is the most reactive metal due to its position in the alkali metal group. It has only been produced in very small amounts in laboratories due to its extreme rarity and radioactivity. Francium reacts vigorously with water, oxygen, and halogens.
2. Fluorine (F): Fluorine is the most reactive non-metal due to its high electronegativity, meaning it readily gains electrons to achieve a stable electron configuration. Fluorine reacts violently with most elements, forming compounds like fluorides.
When considering the reactivity of elements, it's essential to understand their position in the periodic table. Francium is in the alkali metal group, which is known for its high reactivity in general. Fluorine, on the other hand, is a halogen and also highly reactive due to its electron configuration.
Therefore, the correct answer to the question is:
☐ Francium and Flourine
