What are rare earth elements (REE), you might ask? According to the International Union of Pure and Applied Chemistry (IUPAC), REEs include the lanthanide series elements plus two bonus elements (yttrium and scandium). Although they are considered rare, REEs exist...
Chromium (Cr) is a polyvalent element and can exist in several distinct oxidation states, but only trivalent chromium [Cr(III)] and hexavalent chromium [Cr(VI)] occur with any frequency in the natural environment. The...
Although selenium is a component of many minerals, it is only the seventieth most abundant element in the earth’s crust and occurs mostly in small crystals and in small quantities. It typically only occurs at elevated...
Lead (Pb) - is a dense, malleable, and corrosion-resistant metal that has been widely used for thousands of years due to its versatility and low cost. However, it is also highly toxic and poses significant risks to human...
Arsenic is naturally-occurring throughout the environment and also widely used as a preservative for treated wood and as a pesticide in fields where we grow our food. Because of its chemical nature, it is frequently...
Mercury is not very abundant in the planet’s crust; however, even modest increases in the quantity of mercury being introduced into the global environment is a matter of considerable and growing concern. Mercury...