Rn
Noble gas
Radon
Z 86A 222mass 222
Slow-motion stage
Radon-222
proton
neutron
alpha particle (2p + 2n)
Parent nucleus · 222 nucleons
86 protons (coral) and 136 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
22286Rn21884Po+42He
Two protons and two neutrons leave together as one helium nucleus.
Z
8684
-2
A
222218
-4
n⁰
136134
-2
Energy released
5.59MeV
Alpha particle5.489 MeV
Mass convertedE = Δm c²0.00600 u
In joules8.96 × 10-13 J
Compared with a bonda C–C bond is 3.6 eV≈ 1,552,778 ×
Half-life of Radon-222
3.82 days
A gas that seeps out of soil and rock into basements.
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