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How do scientists use half life in radiometric dating

how do scientists use half life in radiometric dating-11

Each of them typically exists in igneous rock, or rock made from cooled magma.Fossils, however, form in sedimentary rock -- sediment quickly covers a dinosaur's body, and the sediment and the bones gradually turn into rock.

But while the difficulties of single life may be intractable, the challenge of determining the age of prehistoric artifacts and fossils is greatly aided by measuring certain radioactive isotopes.Carbon-14 is also passed onto the animals that eat those plants.After death the amount of carbon-14 in the organic specimen decreases very regularly as the molecules decay.Relative age dating also means paying attention to crosscutting relationships.Say for example that a volcanic dike, or a fault, cuts across several sedimentary layers, or maybe through another volcanic rock type.These ions are accelerated in an electric field through collimating slits and subject to a magnetic field which causes the ions to follow a curved path. By adjustment of the strength of the magnetic field and suitable placement of an ion collector, the different isotopes can be measured with precision.

There are some things that affect these measurements.

Carbon-14, or radiocarbon, is a naturally occurring radioactive isotope that forms when cosmic rays in the upper atmosphere strike nitrogen molecules, which then oxidize to become carbon dioxide.

Green plants absorb the carbon dioxide, so the population of carbon-14 molecules is continually replenished until the plant dies.

Until this century, relative dating was the only technique for identifying the age of a truly ancient object.

By examining the object's relation to layers of deposits in the area, and by comparing the object to others found at the site, archaeologists can estimate when the object arrived at the site.

The most widely known form of radiometric dating is carbon-14 dating.