the isotopic ratio of the lead
1Lead-lead dating — is a method for dating geological samples, normally based on whole rock samples of material such as granite. For most dating requirements it has been superseded by uranium lead dating (U Pb dating), but in certain specialized situations (such as… …
2Isotopic dilution — is a technique to increase the precision and accuracy of chemical analysis. First, a known amount of an isotope is added to the sample. For example, to determine the amount of lead in a sample, a known amount of Pb 204, one of the isotopes of… …
3Atomic ratio — The atomic ratio is a measure of the ratio of atoms of one kind (i) to another kind (j). A closely related concept is the atomic percent (or at.%), which gives the percentage of one kind of atom relative to the total number of atoms. The… …
4Isotope-ratio mass spectrometry — Isotope ratio mass spectrometer with gas bench in foreground Acronym IRMS Classification mass spectrometry Other techniques …
5uranium-thorium-lead dating — or common lead dating Method of dating very old rocks by means of the amount of common lead they contain. Common lead is any lead from a rock or mineral that contains a large amount of lead and a small amount of the radioactive precursors of lead …
6Geology of the Moon — The geology of the Moon (sometimes called selenology, although the latter term can refer more generally to lunar science ) is quite different from that of the Earth. The Moon lacks a significant atmosphere and any bodies of water, which… …
7Plutonium in the environment — is an article which is part of the actinides in the environment series. Almost all plutonium present in the environment is due to human activity because the majority of plutonium isotopes are shortlived on a geological timescale.… …
8isotope — isotopic /uy seuh top ik/, adj. isotopically, adv. /uy seuh tohp /, n. Chem. any of two or more forms of a chemical element, having the same number of protons in the nucleus, or the same atomic number, but having different numbers of neutrons in… …
9Kinetic isotope effect — The kinetic isotope effect (KIE) is the ratio of reaction rates of two different isotopically labeled molecules in a chemical reaction. It is also called isotope fractionation, although this term is somewhat broader in meaning. A KIE involving… …
10dating — I In geology and archaeology, the process of determining an object s or event s place within a chronological scheme. Scientists may use either relative dating, in which items are sequenced on the basis of stratigraphic clues (see stratigraphy) or …
