If the thorium-232 isotope emits an alpha particle, what would be the atomic number of the resulting atom?

Answer is: atomic number of resulting atom is 88.
Alpha particle is nucleus of a helium-4 atom, which is made of two protons and two neutrons.
Nuclear reaction: ²³²Th → ²²⁸Ra + α (alpha particle).

Alpha decay is radioactive decay in which an atomic nucleus emits an alpha particle (helium nucleus) and transforms into an atom with an atomic number that is reduced by two and mass number that is reduced by four.

the seeing the electronic configuration we can say that the element is fluorine.

fluorine is the most electronegative element in the periodic table.

but by only seeing the configuration we cannot say about its reactivity because we don't know if its configuration after excitation or by addition of electrons.

but if not then, it is the lightest halogen and exists as a highly toxic pale yellow diatomic gas at standard conditions. as the most electronegative element, it is extremely reactive: almost all other elements, including some noble gases, form compounds with fluorine.