Chemical elements and element groups
Niobium and tantalum: indispensable twins [ More info] Explains why these elements are commonly discussed together, how they are used, where we get them, and prospects for future supply and demand.
Nutrients in the Nation's streams and groundwater: National findings and implications [ More info] Despite public sector efforts to reduce nonpoint-source nutrients in streams and rivers, concentrations have remained the same or increased, continuing to pose risks to aquatic life and human health.
Occurrence, distribution, and concentrations of selected contaminants in streambed- and suspended-sediment samples collected in Bexar County, Texas, 2007-09 [ More info] Study showing which chemicals found in sediments were most common, with methods used and likely consequences of their high concentrations.
Periodic table page [ More info] An "image map" periodic table and short notes about many isotopes and their applications to illustrate the uses of assorted isotopes in hydrology, geology, and biology.
Phosphorus and groundwater: Establishing links between agricultural use and transport to streams [ More info] Explains why phosphorus is important, how it moves through the terrestrial water system, how we measure it, and what this means for people who need to manage or monitor human activities that produce it.
Platinum-group elements: so many excellent properties [ More info] These elements, abbreviated as PGE, include platinum, palladium, rhodium, ruthenium, iridium, and osmium. They have similar physical and chemical properties and occur together in nature.
Preliminary Assessment of Non-Fuel Mineral Resources of Afghanistan, 2007 [ More info] Estimates of known and undiscovered copper resources total nearly 60 million metric tons of copper. Iron resources in known deposits total 2200 million metric tons of ore. Twenty mineralized areas meriting further study were identified.
Principal aquifers can contribute radium to sources of drinking water under certain geochemical conditions [ More info] Knowledge of the geochemical processes controlling radium occurrence in groundwater may help water-resource managers anticipate and minimize human exposure to this cancer-causing element.
Radon in earth, air, and water [ More info] Links to USGS publications, bibliographies, and maps on radon in the U.S., plus links to non-USGS sites with information on radon.
Rare earth elements--End use and recyclability [ More info] Rare earth element use is changing with technology. This report explains how we use them and the prospects for recycling these important commodities.
Alphabetical Index of Topics
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