¹¹²Cs — Unstable · t½ ≈ 500 ms · Decay: β⁺ → ¹¹²Xe · Type: synthetic · Uses: research.
¹¹³Cs — Unstable · t½ ≈ 450 ms · Decay: β⁺ → ¹¹³Xe · Type: synthetic · Uses: research.
¹¹⁴Cs — Unstable · t½ ≈ 570 ms · Decay: β⁺ → ¹¹⁴Xe · Type: synthetic · Uses: research.
¹¹⁵Cs — Unstable · t½ ≈ 1.4 s · Decay: β⁺ → ¹¹⁵Xe · Type: synthetic · Uses: research.
¹¹⁶Cs — Unstable · t½ ≈ 0.7 s · Decay: β⁺ → ¹¹⁶Xe · Type: synthetic · Uses: research.
¹¹⁷Cs — Unstable · t½ ≈ 8.4 s · Decay: β⁺ → ¹¹⁷Xe · Type: synthetic · Uses: research.
¹¹⁸Cs — Unstable · t½ ≈ 14.3 s · Decay: β⁺ → ¹¹⁸Xe · Type: synthetic · Uses: research.
¹¹⁹Cs — Unstable · t½ ≈ 43.0 s · Decay: β⁺ → ¹¹⁹Xe · Type: synthetic · Uses: research.
¹²⁰Cs — Unstable · t½ ≈ 61.0 s · Decay: β⁺ → ¹²⁰Xe · Type: synthetic · Uses: research.
¹²¹Cs — Unstable · t½ ≈ 155 s · Decay: β⁺ → ¹²¹Xe · Type: synthetic · Uses: research.
¹²²Cs — Unstable · t½ ≈ 2.0 min · Decay: β⁺ → ¹²²Xe · Type: synthetic · Uses: research.
¹²³Cs — Unstable · t½ ≈ 5.9 min · Decay: β⁺ → ¹²³Xe · Type: synthetic · Uses: research.
¹²⁴Cs — Unstable · t½ ≈ 30.8 s · Decay: β⁺ → ¹²⁴Xe · Type: synthetic · Uses: research.
¹²⁵Cs — Unstable · t½ ≈ 45.0 min · Decay: β⁺ → ¹²⁵Xe · Type: synthetic · Uses: research.
¹²⁶Cs — Unstable · t½ ≈ 1.64 min · Decay: β⁺ → ¹²⁶Xe · Type: synthetic · Uses: research.
¹²⁷Cs — Unstable · t½ ≈ 6.3 h · Decay: β⁺ → ¹²⁷Xe · Type: activation product · Uses: tracer.
¹²⁸Cs — Unstable · t½ ≈ 3.7 min · Decay: β⁺ → ¹²⁸Xe · Type: synthetic · Uses: research.
¹²⁹Cs — Unstable · t½ ≈ 32.0 h · Decay: β⁻ → ¹²⁹Ba · Type: fission product · Uses: tracer.
¹³⁰Cs — Unstable · t½ ≈ 29.2 min · Decay: β⁻ → ¹³⁰Ba · Type: synthetic · Uses: research.
¹³¹Cs — Unstable · t½ ≈ 9.7 d · Decay: β⁻ → ¹³¹Ba · Type: fission product · Uses: tracer.
¹³²Cs — Unstable · t½ ≈ 6.5 d · Decay: β⁻ → ¹³²Ba · Type: fission product · Uses: tracer.
¹³³Cs — Stable · — · Type: stable (primordial, only stable isotope) · Uses: reference standard, atomic clocks.
¹³⁴Cs — Unstable · t½ ≈ 2.06 y · Decay: β⁻ → ¹³⁴Ba · Type: fission product · Uses: environmental monitoring.
¹³⁵Cs — Unstable · t½ ≈ 2.3×10⁶ y · Decay: β⁻ → ¹³⁵Ba · Type: long-lived fission product · Uses: nuclear waste monitoring.
¹³⁶Cs — Unstable · t½ ≈ 13.0 d · Decay: β⁻ → ¹³⁶Ba · Type: fission product · Uses: tracer.
¹³⁷Cs — Unstable · t½ ≈ 30.1 y · Decay: β⁻ → ¹³⁷Ba · Type: fission product · Uses: environmental monitoring, medical radiotherapy, industrial radiography.
¹³⁸Cs — Unstable · t½ ≈ 33.4 min · Decay: β⁻ → ¹³⁸Ba · Type: synthetic · Uses: research.
¹³⁹Cs — Unstable · t½ ≈ 9.3 min · Decay: β⁻ → ¹³⁹Ba · Type: synthetic · Uses: research.
¹⁴⁰Cs — Unstable · t½ ≈ 63.7 s · Decay: β⁻ → ¹⁴⁰Ba · Type: synthetic · Uses: research.
¹⁴¹Cs — Unstable · t½ ≈ 24.9 s · Decay: β⁻ → ¹⁴¹Ba · Type: synthetic · Uses: research.
¹⁴²Cs — Unstable · t½ ≈ 1.7 s · Decay: β⁻ → ¹⁴²Ba · Type: synthetic · Uses: research.
¹⁴³Cs — Unstable · t½ ≈ 1.2 s · Decay: β⁻ → ¹⁴³Ba · Type: synthetic · Uses: research.
¹⁴⁴Cs — Unstable · t½ ≈ 0.8 s · Decay: β⁻ → ¹⁴⁴Ba · Type: synthetic · Uses: research.
¹⁴⁵Cs — Unstable · t½ ≈ 0.6 s · Decay: β⁻ → ¹⁴⁵Ba · Type: synthetic · Uses: research.
¹⁴⁶Cs — Unstable · t½ ≈ 0.35 s · Decay: β⁻ → ¹⁴⁶Ba · Type: synthetic · Uses: research.
¹⁴⁷Cs — Unstable · t½ ≈ 0.25 s · Decay: β⁻ → ¹⁴⁷Ba · Type: synthetic · Uses: research.
¹⁴⁸Cs — Unstable · t½ ≈ 0.2 s · Decay: β⁻ → ¹⁴⁸Ba · Type: synthetic · Uses: research.
¹⁴⁹Cs — Unstable · t½ ≈ 0.1 s · Decay: β⁻ → ¹⁴⁹Ba · Type: synthetic · Uses: research.
¹⁵⁰Cs — Unstable · t½ ≈ 60 ms · Decay: β⁻ → ¹⁵⁰Ba · Type: synthetic · Uses: research.
¹⁵¹Cs — Unstable · t½ ≈ 50 ms · Decay: β⁻ → ¹⁵¹Ba · Type: synthetic · Uses: research.
Cesium — isotope count: 40 total · Stable: 1 (¹³³Cs) · Unstable: 39.
(Data: IAEA LiveChart, NUBASE2020, ENSDF; notable applications: ¹³³Cs in atomic clocks, ¹³⁷Cs in medicine, industry, and fallout monitoring, ¹³⁴Cs/¹³⁵Cs in environmental studies, long-lived isotopes in nuclear waste.)