unstable
hot
half-life
calcium-45
nonradioactive
radioactive disintegration
nuclear decay
nuclear disintegration
disintegration
beta radiation
iodine-125
radioactive
krypton-85
calcium-48
radioactive material
radiodecay
radioactively
electron radiation
nitrogen-13
beta ray
active material
radioactivating
radioiodine
radioisotope
sulfur-35
alpha radiation
potassium-43
Geiger-Nuttall law
iodine-131
predecay
radioactinium
potassium-40
radiocarbon
carbon 14
radiation
polonium-210
anisotomic
activate
radio-
radiotungsten
Ci
alpha ray
potassium-42
curie
hassium-270
decay constant
radioactivate
radiocontamination
neutron emission
decay