Po
Post-transition metal
Polonium
Z 84A 209mass 209
Slow-motion stage
Polonium-210
proton
neutron
alpha particle (2p + 2n)
Parent nucleus · 210 nucleons
84 protons (coral) and 126 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
21084Po20682Pb+42He
Two protons and two neutrons leave together as one helium nucleus.
Z
8482
-2
A
210206
-4
n⁰
126124
-2
Energy released
5.41MeV
Alpha particle5.304 MeV
Mass convertedE = Δm c²0.00580 u
In joules8.66 × 10-13 J
Compared with a bonda C–C bond is 3.6 eV≈ 1,501,944 ×
Half-life of Polonium-210
138.4 days
The alpha carries 5.3 MeV; the lead-206 recoils with the rest.
The particle
- Charge
- +2
- Mass
- 4 u
- Speed
- About 5% of the speed of light
- Ionising power
- Very high
- Stopped by
- Stopped by a sheet of paper or dead skin