Period 5 element required by higher animals, which use it to synthesize thyroid hormones, which contain the element. Because of this function, radioisotopes of iodine are concentrated in the thyroid gland along with nonradioactive iodine. The radioisotope iodine-131, which has a high fission product yield, concentrates in the thyroid, and is one of the most carcinogenic of nuclear fission products. Xenon has no biological role, and is used as a general anaesthetic. Period 5 element A period 5 element is one of the chemical elements in the fifth row (or "period") of the periodic table of the elements. The periodic table is laid
Extended periodic table (detailed cells) Extended periodic table (detailed cells) This is a large version of the extended periodic table of the chemical elements. For the natural isotopic composition of each element it shows "name", "atomic number", "symbol", "standard atomic weight" (or atomic weight) and a link to the element's isotopes. It also has, by keyed markings, a notification of "occurrence", "state of matter" and "metallic character". It is named "extended" because it shows elements that are theoretical only (in period 8), and "large" means that the table might exceed page width. The presentation is wide which means that there are no table parts separated