Dental amalgam controversy (unlike composites), and is often about 20-30% less expensive. "Consumer Reports" has suggested that many who claim dental amalgam is not safe are "prospecting for disease" and using pseudoscience to scare patients into more lucrative treatment options. Those opposed to amalgam use suggest that modern composites are improving in strength. In addition to their claims of possible health and ethical issues, opponents of dental amalgam fillings claim amalgam fillings contribute to mercury contamination of the environment. The World Health Organization (WHO) reports that health care facilities, including dental offices, account for as much as 5% of total waste water mercury
Chemical element or an electrophile; similarly "Nu" denotes a nucleophile. "L" is used to represent a general ligand in inorganic and organometallic chemistry. "M" is also often used in place of a general metal. At least two additional, two-letter generic chemical symbols are also in informal usage, "Ln" for any lanthanide element and "An" for any actinide element. "Rg" was formerly used for any rare gas element, but the group of rare gases has now been renamed noble gases and the symbol "Rg" has now been assigned to the element roentgenium. Isotopes are distinguished by the atomic mass number (total protons and