Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. 1979, 1986 © Harper Collins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012 Cite This Source (hāf'līf') The average time needed for half the nuclei in a sample of a radioactive substance to undergo radioactive decay.
The half-life of a substance does not equal half of its full duration of radioactivity.
To be able to do this lesson and understand the idea of half-life, students should understand ratios and the multiplication of fractions, and be somewhat comfortable with probability.
) is only 5,730 years—that is, every 5,730 years, half of it decays away.
Geologists believe that the ones we find must have been transported supersonically to the surface, in extremely violent eruptions through volcanic pipes.
Some are found in these pipes, such as kimberlites, while other diamonds were liberated by water erosion and deposited elsewhere (called alluvial diamonds).
As they decay the atoms change to daughter atoms, until eventually there won't be any of the original atoms left.