Radiometric dating often called radioactive dating is a way to find out how old something is. The method compares the amount of a naturally occurring radioactive isotope and its decay products, in samples. The method uses known decay rates. It is used to date many kinds of natural and man-made materials.
Geologist Ralph Harvey and historian Mott Greene explain the principles of radiometric dating and its application in determining the age of Earth. As the uranium in rocks decays, it emits subatomic particles and turns into lead at a constant rate. Measuring the uranium-to-lead ratios in the oldest rocks on Earth gave scientists an estimated age of the planet of 4. Segment from A Science Odyssey: "Origins. View in: QuickTime RealPlayer.
The earth's atmosphere is made up of nitrogen 78 percent , oxygen 21 percent , argon 0. Like pi , e cannot be written exactly in decimal form. The value of e is approximately 2. Like pi , it is one of those numbers that pops up all by itself in nature.
The key difference between carbon dating and uranium dating is that carbon dating uses radioactive isotopes of carbon, whereas uranium dating uses uranium , which is a radioactive chemical element. Carbon dating and uranium dating are two important methods of determining the age of different organic materials. We call them isotopic dating methods.