All isotopes of this period on the periodic table are considered to be radioactive.Group of answer choicesactinideslanthanidesalkalisnoble gases

Which of these chemical elements is not radioactive?

Which of the following is the best description of an isotope?

. Periods on the periodic table represent elements:1 pointin the same groupwith consecutive atomic numbersknown as isotopeswith similar chemical properties

What is the group name, on the periodic table, that contains F, Cl, Br, and I?Group of answer choicesAlkaline Earth MetalsHalogensAlkali MetalsNoble Gases

In elements 1–86 on the periodic table (at 25 °C), one particular group contains one element that forms a diatomic gas in its elemental state, at least one metalloid, two nonmetal solids that are not metalloids, and one element that is exclusively radioactive.  The group is:A.Group 14.B.Group 15.C.Group 16.D.Group 17.