unbinilium ← unbiunium → unbibium - ↑ Ubu ↓ Usu 121Ubu Periodic table
Appearance
General properties
Name, symbol, number	unbiunium, Ubu, 121
Element category	superactinides
Group, period, block	n/a, 8, g
Standard atomic weight	unknown g·mol−1
Electron configuration	[Uuo] 5g1 8s2 (predicted)
Electrons per shell	2, 8, 18, 32, 32, 18, 9, 2 (predicted) (Image)
Physical properties
Atomic properties
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Unbiunium (pronounced /uːnbaɪˈuːniəm/) is the temporary name of a hypothetical chemical element in the periodic table that has the temporary symbol Ubu and has the atomic number 121.

Unbiunium is the first element whose ground state electron configuration contains an electron in a g subshell, making it the first element in the g-block. However, neither lanthanum nor actinium show such a predicted ground state for the f-block, and lie in the transition metals, so unbiunium's third electron should also hang up. Other elements have access to their g subshells, though not in their ground states. Calculations have shown that ³²⁰Ubu would be the most stable isotope.

As of November 2009, no attempt has ever been made to synthesize element 121.

Contents 1 Naming 2 Target-projectile combinations leading to Z=121 compound nuclei 3 External links 4 See also

[edit] Naming

The name unbiunium is a systematic element name, used as a placeholder until it is confirmed by other research groups and the IUPAC decides on a name. Usually, the name suggested by the discoverer(s) is chosen.

[edit] Target-projectile combinations leading to Z=121 compound nuclei

The below table contains various combinations of targets and projectiles which could hypothetically be used to form compound nuclei with Z=121.

Target-projectile combinations leading to Z=121 nuclei

Target	Projectile	CN	Attempt result
208Pb	89Y	297121	Reaction yet to be attempted
232Th	71Ga	303121	Reaction yet to be attempted
238U	65Cu	303121	Reaction yet to be attempted
237Np	64Ni	301121	Reaction yet to be attempted
244Pu	59Co	303121	Reaction yet to be attempted
243Am	58Fe	301121	Reaction yet to be attempted
248Cm	55Mn	303121	Reaction yet to be attempted
249Bk	54Cr	303121	Reaction yet to be attempted
249Cf	51V	300121	Reaction yet to be attempted
254Es	50Ti	304121	Reaction yet to be attempted

[edit] External links

• Journal of Chemical Physics, 1998, V 109, N 10, 8 Sep.

[edit] See also

• unbinilium–unbibium