Which METAL is the MOST REACTIVE? (Most likely to form chemical bonds to result in a full outer energy level)
A)Li (Lithium)
B)Al (Aluminum)
C)Fr (Francium)
D)F (Fluorine)

Explanation:

Fluorine (F) is not a metal; thus, the last option is discarded quickly.

The most reactive metals are the alkali metals, group 1 of the periodic table, because they have just one valence electron, which they can release more easily than other metals which have more valence electrons.

Lithium(Li) and francium (Fr) are alkali metals, while aluminum (Al) belongs to group 13, which means that it has 3 valence electrons.

Thus, aluminum is out of race too.

Lithium is in the second period (row 2 of the periodic table) while francium is in the last period (row 7).

The reactivity of metals in a group increases from top to bottom, because the valence electrons are shielded by many electrons (which are in the orbitals of less energy and closer to the nucleus of the atom), meaning that the valence eletrons can be released more easily.

Hence, the most reactive metal from the list is Fr (francium), option C).

it is stable as it is in group 0 which have full outer shells of electrons