<Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> <P> A period 7 element is one of the chemical elements in the seventh row (or period) of the periodic table of the chemical elements . The periodic table is laid out in rows to illustrate recurring (periodic) trends in the chemical behaviour of the elements as their atomic number increases: a new row is begun when chemical behaviour begins to repeat, meaning that elements with similar behaviour fall into the same vertical columns . The seventh period contains 32 elements, tied for the most with period 6, beginning with francium and ending with oganesson, the heaviest element currently discovered . As a rule, period 7 elements fill their 7s shells first, then their 5f, 6d, and 7p shells, in that order; however, there are exceptions, such as plutonium . </P> <P> All elements of period 7 are radioactive . This period contains the actinides, which contains the heaviest naturally occurring element, plutonium; subsequent elements must be synthesized artificially . Whilst the first five of these are now available in macroscopic quantities, most are extremely rare, having only been prepared in microgram amounts or less . The later, transactinide elements have only been identified in laboratories in batches of a few atoms at a time . </P> <P> Although the rarity of many of these elements means that experimental results are not very extensive, their periodic and group trends are less well defined than other periods . Whilst francium and radium do show typical properties of their respective groups, actinides display a much greater variety of behaviour and oxidation states than the lanthanides . These peculiarities are due to a variety of factors, including a large degree of spin - orbit coupling and relativistic effects, ultimately caused by the very high positive electrical charge from their massive atomic nuclei . </P>

What is the largest metalloid on the periodic table