I
Halogen
Iodine
Z 53A 127mass 126.9
Slow-motion stage
Iodine-131
proton
neutron
electron (β⁻)
Parent nucleus · 131 nucleons
53 protons (coral) and 78 neutrons (blue) are packed together and held by the strong force.
A real decay takes about 10⁻²¹ s. At ⅓× this stage stretches it across eleven seconds.
Choose a reaction
Reaction
13153I13154Xe+β⁻+ ν̄
A neutron turns into a proton. An electron and an antineutrino fly out.
Z
5354
+1
A
131131
no change
n⁰
7877
-1
Energy released
0.971MeV
Electron (max)0.971 MeV
Mass convertedE = Δm c²0.00104 u
In joules1.56 × 10-13 J
Compared with a bonda C–C bond is 3.6 eV≈ 269,722 ×
Half-life of Iodine-131
8.02 days
Concentrates in the thyroid gland; used to treat it too.
The particle
- Charge
- −1
- Mass
- 1/1836 u
- Speed
- Up to 99.9% of the speed of light
- Ionising power
- Moderate
- Stopped by
- A few millimetres of aluminium