Radioactive tracer such as a cell or tissue, or as a flow tracer to track fluid flow. Radioactive tracers are also used to determine the location of fractures created by hydraulic fracturing in natural gas production. Radioactive tracers form the basis of a variety of imaging systems, such as, PET scans, SPECT scans and technetium scans. Radiocarbon dating uses the naturally occurring carbon-14 isotope as an isotopic label. Isotopes of a chemical element differ only in the mass number. For example, the isotopes of hydrogen can be written as H, H and H, with the mass number at top left. When the
Archaeological science archaeological strata and artifacts. Some of the most important dating techniques include: Another important subdiscipline of archaeometry is the study of artifacts. Archaeometrists have used a variety of methods to analyze artifacts, either to determine more about their composition, or to determine their provenance. These techniques include: Lead, strontium and oxygen isotope analysis can also test human remains to estimate the diets and even the birthplaces of a study's subjects. Provenance analysis has the potential to determine the original source of the materials used, for example, to make a particular artifact. This can show how far the artifact has traveled