Because of its relatively short half-life of 5730 years, 14C is virtually absent in ancient rocks, but is created in the upper atmosphere (lower stratosphere and upper troposphere) by interaction of nitrogen with cosmic rays.. 
Magenọmú (, ) je àpilẹ̀ṣe kẹ́míkà pelu ami-ìdámọ̀ Satan, nọmba átọ́tọ́ 12 ati nọmba isodo-jini wíwọ́pọ̀ +2.. 