What does plutonium-238 decay into?

Plutonium-238 does not occur in nature as it decays relatively quickly into lead, according to Chemicool. Before its final decay into lead, which is stable, Pu-238 cascades through a number of daughter elements with varying half-lives of their own. Pu-238 emits alpha particles with every decay event.

According to Texas Radiation Online, plutonium-238 has a half-life of only 88 years. As it decays, Pu-238 emits radiation and becomes uranium-234. U-234 has a half-life of 245,000 years before it emits radiation and decays into thorium-230, which has a half-life of 75,400 years. Th-230, in turn, decays into radium-226 with a half-life of 1,607 years. Finally, the sample decays one last time into lead, which is stable indefinitely.