Ununtrium

Ununtrium

Ununtrium is the temporary name of a synthetic element with the temporary symbol Uut and atomic number 113.It is placed as the heaviest member of the group 13 elements although a sufficiently stable isotope is not known at this time that would allow chemical experiments to confirm its position...

(Uut) is an artificial element, and thus a standard atomic mass

Atomic mass

The atomic mass is the mass of a specific isotope, most often expressed in unified atomic mass units. The atomic mass is the total mass of protons, neutrons and electrons in a single atom....

 cannot be given. Like all artificial elements, it has no stable isotope

Stable isotope

Stable isotopes are chemical isotopes that may or may not be radioactive, but if radioactive, have half-lives too long to be measured.Only 90 nuclides from the first 40 elements are energetically stable to any kind of decay save proton decay, in theory...

s. The first isotope

Isotope

Isotopes are variants of atoms of a particular chemical element, which have differing numbers of neutrons. Atoms of a particular element by definition must contain the same number of protons but may have a distinct number of neutrons which differs from atom to atom, without changing the designation...

 to be synthesized was ²⁸⁴Uut as a decay product

Decay product

In nuclear physics, a decay product is the remaining nuclide left over from radioactive decay. Radioactive decay often involves a sequence of steps...

 of ²⁸⁸Uup in 2003. The first isotope to be directly synthesized was ²⁷⁸Uut in 2004. There are 6 known radioisotopes from ²⁷⁸Uut to ²⁸⁶Uut. The longest-lived isotope is ²⁸⁶Uut with a half-life

Half-life

Half-life, abbreviated t½, is the period of time it takes for the amount of a substance undergoing decay to decrease by half. The name was originally used to describe a characteristic of unstable atoms , but it may apply to any quantity which follows a set-rate decay.The original term, dating to...

 of 19.6 seconds.

Table

nuclide symbol	Z(p Proton The proton is a subatomic particle with the symbol or and a positive electric charge of 1 elementary charge. One or more protons are present in the nucleus of each atom, along with neutrons. The number of protons in each atom is its atomic number.... )	N(n Neutron The neutron is a subatomic hadron particle which has the symbol or , no net electric charge and a mass slightly larger than that of a proton. With the exception of hydrogen, nuclei of atoms consist of protons and neutrons, which are therefore collectively referred to as nucleons. The number of... )	isotopic mass (u)	half-life	decay mode(s)	daughter isotope(s)	nuclear spin
278Uut	113	165		340 µs	α Alpha decay Alpha decay is a type of radioactive decay in which an atomic nucleus emits an alpha particle and thereby transforms into an atom with a mass number 4 less and atomic number 2 less...	274Rg
282Uut	113	169		73 ms	α	278Rg
283UutNot directly synthesized, occurs as decay product Decay product In nuclear physics, a decay product is the remaining nuclide left over from radioactive decay. Radioactive decay often involves a sequence of steps...  of 287Uup	113	170	283.17645(78)#	100(+490-45) ms	α	279Rg
284UutNot directly synthesized, occurs as decay product of 288Uup	113	171	284.17808(86)#	0.48(+58-17) s	α	280Rg
285UutNot directly synthesized, occurs in decay chain Decay chain In nuclear science, the decay chain refers to the radioactive decay of different discrete radioactive decay products as a chained series of transformations... of 293Uus	113	172	285.17873(105)#	5.5 s	α	281Rg
286UutNot directly synthesized, occurs in decay chain of 294Uus	113	173	286.18048(101)#	19.6 s	α	282Rg

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