Respuesta :
Silicon and germanium are metalloids.
Atomic radius increases because there are more electron shells.
Four valence electrons.
66) An element in group 14 that can be classified as a Metalloid is; Silicon and Germanium.
67) The reason why atomic radius increases with successive elements in group 14 is because; the number of energy levels (n) increases because there are more electron shells.
68) The expected number of valence electrons in an atom of Flerovium in the ground state is; 4 valence electrons.
66) The elements in group 14 of the periodic table are; Carbon, Silicon, Germanium, Tin, Lead, Flerovium.
Among all these elements, the only one that is a Metalloid is Silicon and Germanium.
67)When moving down a group in the periodic table, the number of energy levels (n) increases because there are more electron shells and as a result, there will be a greater distance between the nucleus and the outermost orbital. This distance is called atomic radius and it means it increases down a group.
68) Flerovium has 114 electrons and the shell structure is; 2, 8, 18, 32, 32, 18, 4.
4 is the last number and as such it has 4 valence electrons in it's outermost shell.
Read more about atomic radius down a group at; https://brainly.com/question/22632407