In fact, the chemical techniques pioneered by nuclear chemists have become so important that biologists, geologists, and physicists use nuclear chemistry as ordinary tools of their disciplines.
While the common perception is that nuclear chemistry involves only the study of radioactive nuclei, advances in modern mass spectrometry instrumentation has made chemical studies using stable, nonradioactive isotopes increasingly important.
There are essentially three sources of radioactive elements.
Primordial nuclides are radioactive elements whose half-lives are comparable to the age of our solar system and were present at the formation of Earth.
It was first prepared in pure form in 1807 by English chemist Sir Humphry Davy (1778-1829).
That's what we've believed for some time - but recent research makes us wonder if this is true after all.The average atomic mass for the element is actually 12.011.Since you never really know which carbon atom you are using in calculations, you should use the average mass of an atom.There is some evidence of slight seasonal variations in the rates of radioactive decay of some isotopes, which may be due to temperature differences. Or may be due to something else we don't know about yet.For now, for GCSE exams, let's go along with the idea that the rate of radioactive decay does not depend on external factors.
(See sidebar on Davy in the calcium entry in Volume 1.) There are very few uses for potassium as a pure element.