what examples are there for exponential decay?

Answer 1

exponential decay is most commonly associated with radioactive decay and half-lives

Answer 2

All radioactivity. For example, bombardment of the upper atmospheric nitrogen by cosmic rays produces radioactive carbon-14. Plants on the earth incorporate carbon-14 dioxide into their tissues along with ordinary carbon-12 by photosynthesis. When ancient Egyptians made dead reeds into papyrus, wrote texts on the papyrus, and put the papyrus texts into pyramids, the carbon-14 began to decay with a half-life of 5400 years. The decay is exponential, because half the carbon-14 decays in the first 5400 years, and half of that in the next 5400 years.

Answer 3

exponential decays are in radioactive or nuclear decay theaory (this is one case)
and another is it may be associated with analytical geometry such as in parabola, hyperbola..etc

Answer 4

Please refer this.