Group 12 element of 40 mg/day. Mercury and cadmium are toxic and may cause environmental damage if they enter rivers or rain water. This may result in contaminated crops as well as the bioaccumulation of mercury in a food chain leading to an increase in illnesses caused by mercury and cadmium poisoning. Group 12 element Group 12, by modern IUPAC numbering, is a group of chemical elements in the periodic table. It includes zinc (Zn), cadmium (Cd) and mercury (Hg). The further inclusion of copernicium (Cn) in group 12 is supported by recent experiments on individual copernicium atoms. Formerly this group was named
Extended periodic table neutron drip lines and stability toward alpha decay and spontaneous fission. One calculation by Y. Gambhir et al., analyzing nuclear binding energy and stability in various decay channels, suggests a limit to the existence of bound nuclei at "Z" = 146. Some, such as Walter Greiner, predicted that there may not be an end to the periodic table. Other predictions of an end to the periodic table include "Z" = 128 (John Emsley) and "Z" = 155 (Albert Khazan). It is a "folk legend" among physicists that Richard Feynman suggested that neutral atoms could not exist for atomic numbers greater