Assertion: natural transmutation | /r/HasProperty | mediated by production of carbon-14
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Source sentences:
text: Most natural transmutation on the Earth today is mediated by cosmic rays (such as production of carbon-14) and by the radioactive decay of radioactive primordial nuclides left over from the initial formation of the solar system (such as potassium-40, uranium and thorium), plus the radioactive decay of products of these nuclides (radium, radon, polonium, etc.).