Atomic and nuclear properties of the neutron (
n
):
Quantity
Value
Units
Value
Units
Atomic number
0
n
n
n
Mass
+/-
1.008 664 915 95 (49)
u
+/-
939.565 420 52 (54)
MeV
Nuclear density
mmm
few x 10
15
g cm
-3
n
n
Mass values from
2018 CODATA
Mean life 878.4 ± 0.5 s (PDG 2024; error includes scale factor of 1.8)