Answer:
The two elements that are most likely to react and form a compound are lithium Li and fluorine F, forming an ionic compound.
Explanation:
Valencia electrons are the electrons found in the last electronic layer (called valence orbitals). These electrons are what determine the ability of the atom to form bonds. When an element joins another, it does so through its valence electrons. It is also possible to say that these electrons are the electrons furthest from the nucleus of the atom, which is why they participate in chemical reactions.
An ionic bond is produced between metallic and non-metallic atoms, where electrons are completely transferred from one atom to another. During this process, one atom loses electrons and another one gains them, forming ions. Usually, the metal gives up its electrons forming a cation to the nonmetal element, which forms an anion. In this way, the octet rule is fulfilled, which establishes that the atoms of the elements bind each other in the attempt to complete their valence layer, leaving the atom stable with 8 electrons in its last layer.
In this case, lithium Li is a metal that has only one electron, which can be transferred to fluorine F through an ionic bond, because as can be seen in the figure, it has 7 electrons in its valence layer. In this way both elements get stability.
Then, <u><em>the two elements that are most likely to react and form a compound are lithium Li and fluorine F, forming an ionic compound.</em></u>
