Search the Web with our sponsor, Overture. Click on an underlined word for more information on that subject. The half-life of a radioisotope is the amount of time it takes for half of the radioisotope to decay.
Volcanoes often erupt over hot spots.
As stated in our privacy policy , we fully respect your privacy and will not use your e-mail address for any purpose other than the newsletter subscription. Search the Web with our sponsor, Overture. Search the Web. Search the Web with our sponsor, Overture. Without our visitors' support, Enchanted Learning would soon be off-line.