Very few atoms of the element tennessine (Ts) have ever been identified. The atomic number of tennessine is 117. Predict the number of outer shell electrons in an atom of tennessine. Give one reason for your answer. Use the periodic table.

For main group elements in the periodic table, the Group number indicates the number of electrons in the outermost shell (valence electrons).\n1. Locating element 117 (Tennessine, Ts) on the periodic table shows that it is in Group 17 (or Group 7).\n2. All elements in Group 17, also known as the halogens, have 7 electrons in their outer shell.\n3. Therefore, we can predict that tennessine will also have 7 outer shell electrons.