Final answer:
Tennessine (Tn) is an extremely unstable synthetic element with atomic number 117. It belongs to Group 17 in the periodic table and is predicted to have a valence electron configuration of [Rn] 7s^2 5f^14 6d^10 7p^5. Tennessine is classified as a halogen.
Step-by-step explanation:
Tennessine (Tn) is an extremely unstable synthetic element with atomic number 117. Being an element in the superheavy region, it is predicted to have properties that align with the trends observed in the periodic table. As a Group 17 element, it is expected to have a valence electron configuration of [Rn] 7s25f146d107p5. Tennessine is classified as a halogen, similar to chlorine and fluorine, which are in the same group.