by Dr. Andrew A. Snelling on October 1, 2012; a 2 minute read
During the radioactive decay of uranium and thorium contained in rocks, lots of helium is produced. Because helium is the second lightest element and a noble gas—meaning it does not combine with other atoms—it readily diffuses (leaks) out and eventually escapes into the atmosphere. Helium diffuses so rapidly that all the helium should have leaked out in less than 100,000 years. So why are these rocks still full of helium atoms? Continue reading at answersingenesis.org.