Compare and contrast the use of U-238 and C-14 in absolute age dating

Carbon-14 and Uranium-238 have something we call a half live, which is basically a known time period for it to change half of its C-14 or U-238 radioactively decay. Since we know how long that is 5730 years for Carbon-14 for half a sample to deteriorate, than we can figure out how old it is.

Explained

Explanation:

Carbon dating C-14 is done to find the age of relatively younger fossils and rocks. Half life of C-14 is only 5700 years and can only be used to date fossils of about 50,000 years old. Where as Uranium-238 has half life of about 4.5 billion years. If 50% of U-238 is left in sample it means that the sample is 4.5 billion year old. It is to be noted that no fossils contain U-238 in it. It is contained only in the igneous and volcanic rocks. So no fossils can be dated using U-238.