Element of the week: ununseptium (2024)

Berkelium. It took 250 days to make enough berkelium, shown here (just 22 milligrams, dissolved), to synthesize element 117.
Image: ORNL, Department of Energy (public domain).

This week's element is ununseptium, a superheavy synthetic chemical element that has the temporary symbol, Uus, and the permanent atomic number, 117. This is the penultimate element that we will meet in this series.

This element's chemical properties are not known at this time, but it is part of the halogen group, so it may have similar characteristics (although its large size probably causes significant changes). This element is currently thought of as a metalloid.

The chemistry of this super-heavy element is not nearly as interesting to non-physicists and non-chemists as the bureaucratic red tape surrounding one of its parents. By this, I am referring to the target used in the synthesis of this element. This target was berkelium-249, which was synthesised and purified in the United States at Oak Ridge National Laboratories (ORNL) -- a process that took at least 180 days -- before it was sent to Russia to be prepared for synthesis by the team at the Flerov Laboratory of Nuclear Reactions (JINR) in Dubna.

Keep in mind that berkelium-249 has a half-life of 330 days, which means that half of it decays into other, smaller elements after that time had passed.

The berkelium-249 target was packed into five lead containers in 2009 and was sent from New York City to Moscow on a commercial airliner. And then the Russian customs officers refused it entry into the country because it was not accompanied by the correct paperwork.

So it was sent back to the United States, where it was given additional paperwork, and then sent back to Moscow. Once again, it was refused entry into the country because it was accompanied by incomplete paperwork. So once again, it was sent back to New York City, where additional paperwork was provided before it was sent back to Moscow yet again.

This time, the Russian customs agents allowed it entry into the country, where then it was prepared for synthesis and then bombarded with calcium-48, creating what appeared to be six atoms of element 117.

Here's two of our favourite chemistry professors, telling us a little more about this new element:

[Video link]

.. .. .. .. .. .. .. .. .. .. .. ..

Video journalist Brady Haran is the man with the camera and the University of Nottingham is the place with the chemists. You can follow Brady on twitter @periodicvideos and the University of Nottingham on twitter @UniofNottingham

You've already met these elements:

Livermorium: Lv, atomic number 116
Ununpentium: Uup, atomic number 115
Flerovium: Fl, atomic number 114
Ununtrium: Uut, atomic number 113
Copernicium: Cn, atomic number 112
Roentgenium: Rg, atomic number 111
Darmstadtium: Ds, atomic number 110
Meitnerium: Mt, atomic number 109
Hassium: Hs, atomic number 108
Bohrium: Bh, atomic number 107
Seaborgium: Sg, atomic number 106
Dubnium: Db, atomic number 105
Rutherfordium: Rf, atomic number 104
Lawrencium: Lw, atomic number 103
Nobelium: No, atomic number 102
Mendelevium: Md, atomic number 101
Fermium: Fm, atomic number 100
Einsteinium: Es, atomic number 99
Californium: Cf, atomic number 98
Berkelium: Bk, atomic number 97
Curium: Cm, atomic number 96
Americium: Am, atomic number 95
Plutonium: Pu, atomic number 94
Neptunium: Np, atomic number 93
Uranium: U, atomic number 92
Protactinium: Pa, atomic number 91
Thorium: Th, atomic number 90
Actinium: Ac, atomic number 89
Radium: Ra, atomic number 88
Francium: Fr, atomic number 87
Radon: Rn, atomic number 86
Astatine: As, atomic number 85
Polonium: Po, atomic number 84
Bismuth: Bi, atomic number 83
Lead: Pb, atomic number 82
Thallium: Tl, atomic number 81
Mercury: Hg, atomic number 80
Gold: Au, atomic number 79
Platinum: Pt, atomic number 78
Iridium: Ir, atomic number 77
Osmium: Os, atomic number 76
Rhenium: Re, atomic number 75
Tungsten: W, atomic number 74
Tantalum: Ta, atomic number 73
Hafnium: Hf, atomic number 72
Lutetium: Lu, atomic number 71
Ytterbium: Yb, atomic number 70
Thulium: Tm, atomic number 69
Erbium: Er, atomic number 68
Holmium: Ho, atomic number 67
Dysprosium: Dy, atomic number 66
Terbium: Tb, atomic number 65
Gadolinium: Gd, atomic number 64
Europium: Eu, atomic number 63
Samarium: Sm, atomic number 62
Promethium: Pm, atomic number 61
Neodymium: Nd, atomic number 60
Praseodymium: Pr, atomic number 59
Cerium: Ce, atomic number 58
Lanthanum: La, atomic number 57
Barium: Ba, atomic number 56
Cæsium: Cs, atomic number 55
Xenon: Xe, atomic number 54
Iodine: I, atomic number 53
Tellurium: Te, atomic number 52
Antimony: Sb, atomic number 51
Tin: Sn, atomic number 50
Indium: In, atomic number 49
Cadmium: Cd, atomic number 48
Silver: Ag, atomic number 47
Palladium: Pd, atomic number 46
Rhodium: Rh, atomic number 45
Ruthenium: Ru, atomic number 44
Technetium: Tc, atomic number 43
Molybdenum: Mo, atomic number 42
Niobium: Ni, atomic number 41
Zirconium: Zr, atomic number 40
Yttrium: Y, atomic number 39
Strontium: Sr, atomic number 38
Rubidium: Rr, atomic number 37
Krypton: Kr, atomic number 36
Bromine: Br, atomic number 35
Selenium: Se, atomic number 34
Arsenic: As, atomic number 33
Germanium: Ge, atomic number 32
Gallium: Ga, atomic number 31
Zinc: Zn, atomic number 30
Copper: Cu, atomic number 29
Nickel: Ni, atomic number 28
Cobalt: Co, atomic number 27
Iron: Fe, atomic number 26
Manganese: Mn, atomic number 25
Chromium: Cr, atomic number 24
Vanadium: V, atomic number 23
Titanium: Ti, atomic number 22
Scandium: Sc, atomic number 21
Calcium: Ca, atomic number 20
Potassium: K, atomic number 19
Argon: Ar, atomic number 18
Chlorine: Cl, atomic number 17
Sulfur: S, atomic number 16
Phosphorus: P, atomic number 15
Silicon: Si, atomic number 14
Aluminium: Al, atomic number 13
Magnesium: Mg, atomic number 12
Sodium: Na, atomic number 11
Neon: Ne, atomic number 10
Fluorine: F, atomic number 9
Oxygen: O, atomic number 8
Nitrogen: N, atomic number 7
Carbon: C, atomic number 6
Boron: B, atomic number 5
Beryllium: Be, atomic number 4
Lithium: Li, atomic number 3
Helium: He, atomic number 2
Hydrogen: H, atomic number 1

Here's the Royal Society of Chemistry's interactive Periodic Table of the Elements that is just really really fun to play with!

GrrlScientist can also be found here: Maniraptora. She's very active on twitter @GrrlScientist and sometimes lurks on social media: facebook, G+, LinkedIn, Pinterest.