Np
Actinide
Neptunium
Z 93A 237mass 237
Slow-motion stage
Neptunium-237
proton
neutron
alpha particle (2p + 2n)
Parent nucleus · 237 nucleons
93 protons (coral) and 144 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
23793Np23391Pa+42He
Two protons and two neutrons leave together as one helium nucleus.
Z
9391
-2
A
237233
-4
n⁰
144142
-2
Energy released
4.96MeV
Alpha particle4.875 MeV
Mass convertedE = Δm c²0.00532 u
In joules7.95 × 10-13 J
Compared with a bonda C–C bond is 3.6 eV≈ 1,377,500 ×
Half-life of Neptunium-237
2.14 million years
A long-lived transuranic waste product.
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