²⁹³Ts — Unstable · t½ ≈ 14 ms · Decay: α → ²⁸⁹Mc · Type: synthetic · Uses: research.
²⁹⁴Ts — Unstable · t½ ≈ 78 ms · Decay: α → ²⁹⁰Mc · Type: synthetic · Uses: longest-lived Ts isotope, superheavy element studies.
Tennessine — isotope count: 2 total · Stable: none · Unstable: 2.
(Data: IAEA LiveChart, NUBASE2020, ENSDF, Wikipedia “Isotopes of tennessine.” Notable applications: all isotopes are synthetic and extremely short-lived; ²⁹⁴Ts is longest-lived, enabling limited nuclear and chemical investigations.)