An isotope that is radioactive and gives off radioactivity until stability is reached
Matter that is capable of undergoing spontaneous change, as in a radioactive nuclide or an excited nuclear system An unstable particle is any elementary particle that spontaneously decays into other particles
a chemical which is the pure state, or as produced or transported, will vigorously polymerize, decompose, condense, or will become self-reactive under conditions of shocks, pressure or temperature
A chemical that, in its pure state or as commercially produced, will react vigorously in some hazardous way under shock conditions (i e , dropping), certain temperatures, or pressures
If people are unstable, their emotions and behaviour keep changing because their minds are disturbed or upset. He was emotionally unstable stable
A chemical that in the pure state, or as produced or transported, will vigorously polymerize, decompose, condense, or will become self-reactive under conditions of shocks, pressure, or temperature
Tending toward decomposition or other unwanted chemical change during normal handling or storage
disposed to psychological variability; "his rather unstable religious convictions"