362 | The History and Use of Our Earth’s Chemical Elements not long after the announcement of their discoveries, the publication Physical Review Letters

362 | The History and Use of Our Earth’s Chemical Elements not long after the announcement of their discoveries, the publication Physical Review Letters

received correspondence that announced the retraction of the discovery of these elements. This retraction was the result of the Berkeley team’s inability to reproduce the results. Since element 116 is part of the decay chain of element 118, its existence is also problematic. See the entry for element 118 for more detail on this issue.

Common฀Uses Since isotopes of element 116 may not have been produced, there are no uses for it.

Examples฀of฀Compounds None.

Hazards There is no hazard to the general public because of the scarcity or nonexistence of unun-

hexium’s isotopes, which are used only in nuclear laboratories. UNUNSEPTIUM฀( 117 UUS)

SYMBOL:฀Uus฀ PERIOD:฀7฀ SERIES฀NAME:฀Superactinide฀ ฀ATOMIC฀NO:฀117 ATOMIC฀MASS:฀Unknown฀ VALENCE:฀Unknown฀ OXIDATION฀STATE:฀Unknown฀ ฀

NATURAL฀STATE:฀Expected฀to฀be฀a฀solid฀silvery฀metal ORIGIN฀OF฀NAME:฀Under฀the฀IUPAC’s฀temporary฀system,฀it฀is฀assigned฀the฀name฀“unun- septium”฀(117). ISOTOPES:฀Not฀yet฀produced.

ELECTRON฀CONFIGURATION ฀ Energy฀Levels/Shells/Electrons฀ Orbitals/Electrons

s2,฀p6

฀ 3-M฀=฀18฀

s2,฀p6,฀d10

฀ 4-N฀=฀32฀

s2,฀p6,฀d10,฀f14

฀ 5-O฀=฀32฀

s2,฀p6,฀d10,฀f14

฀ 6-P฀=฀18฀

s2,฀p6,฀d10

฀ 7-Q฀=฀7฀

s2,฀p5

Properties฀and฀Characteristics Because element 117 (ununseptium) has not yet been produced, its properties are not

known. This does not hinder speculation as to what some of the properties and characteristics of 117 Uus will be when it is discovered and where it will fit into the scheme of what is known of elements 116 and 118—if they are confirmed. One thing that can be assumed with a high degree of probability is that Uus does not have a “magic number” of protons and neutrons, and thus is not included as one of the elements in the “island of stability.”

363 History

Guide to the Elements |

There is little history to report, except so far, its artificial production has not been reported. It is expected to be an extension of the halogens and will be located at the bottom of group 17(VIIA).

Common฀Uses None, except as a “place filler” between Z-116 and Z-118 in the periodic table. Examples฀of฀Compounds None. Hazards None, because it does not seem to exist. UNUNOCTIUM฀( 118 UUO) SYMBOL:฀Uuo฀ PERIOD:฀7฀ SERIES฀NAME:฀Superactinide฀ ATOMIC฀NO:฀118

ATOMIC฀MASS:฀Unknown฀ VALENCE:฀Unknown฀ OXIDATION฀STATE:฀Unknown฀ NATU- RAL฀STATE:฀Expected฀to฀be฀a฀gas ORIGIN฀OF฀NAME:฀Ununoctium฀(118)฀follows฀the฀temporary฀naming฀system฀of฀IUPAC฀for฀ elements฀that฀have฀not฀yet฀received฀proper฀names. ISOTOPES:฀No฀isotopes฀of฀ununoctium฀have฀yet฀been฀produced.

ELECTRON฀CONFIGURATION ฀ Energy฀Levels/Shells/Electrons฀ Orbitals/Electrons

s2,฀p6

฀ 3-M฀=฀18฀

s2,฀p6,฀d10

฀ 4-N฀=฀32฀

s2,฀p6,฀d10,฀f14

฀ 5-O฀=฀32฀

s2,฀p6,฀d10,฀f14

฀ 6-P฀=฀18฀

s2,฀p6,฀d10

฀ 7-Q฀=฀8฀

s2,฀p6

Properties฀and฀Characteristics Not only is ununoctium expected to be a gas, but it should also be a nonmetal when

discovered. It is located at the bottom of group 18 (VIIIA) in the periodic table and could

be expected to have some of the characteristics of it neighbors above it in this group. When first and erroneously reported as being discovered, it was said to have 118 protons and 175 neutrons in its nucleus for an atomic mass number (amu) of ˜293, which would make it the heaviest of the yet-to-be discovered elements.