Period 7 Element - Properties

Properties

All elements of period 7 are radioactive. This period contains the actinides, which contains the heaviest naturally occurring element, californium; subsequent elements must be synthesized artificially. Whilst one of these (einsteinium) is 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: of these, ununtrium, ununpentium and those beyond livermorium have not been recognised by the IUPAC.

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. Studies conducted on flerovium demonstrate some noble gas behaviour, while analogous tests on ununoctium show non-noble gas characteristics. 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.