The al2o3 crystal structure (corundum) consists of an hcp arrangement of o2- ions; the al3+ ions occupy octahedral positions. what fraction of the available octahedral positions are filled with al3+ ions? in corundum, the al3+ ions do not fill the tetrahedral positions.

plasma - state of matter made up of electrically charged particles

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.