The Elements| The Elements |
In General > s.a. atomic physics.
* Origin: Nucleosynthetic
processes in the course of the evolution of the Universe and the galaxies
contained within include primordial nucleosynthesis, stellar evolution,
and explosive nucleosynthesis in single and binary systems.
* Superheavy elements:
The search is fascinating, and offers sensitive tests of theories of
nuclear physics and chemistry (for example by observing their decays),
but experiments typically last several months, and at the end produce
few, of the order of two or three, superheavy nuclei.
* Naming: Names must end in
"-ium," "-ine," or "-on" depending on the grouping of elements they belong to.
@ General references:
Ball 04;
Rauscher & Patkós in(11)-a1011,
Woosley et al PT(19)feb [origin].
@ Periodic system:
Babaev & Hefferlin in(96);
Scerri AS(97) [and electrons],
SA(98)sep [evolution];
Kak Sandhan(04)phy [history, Mendeleev];
Kibler FC(07)qp/06 [application of SO(4,2) × SU(2)];
Scerri AS(08)jan [history and developments in classification system];
Kragh a1207/EPJH [early scientific interest in the very heavy elements];
Lagerkvist 12 [and Mendeleev];
news sn(19)jan,
pt(19)mar [history].
@ New elements:
news cnn(16)jun [113, 115, 117, 118 named];
Kragh a1708 [the search for superheavy elements].
@ Related topics: Oganessian & Rykaczewski PT(15)aug [island of stability];
He & Garoufalidis a1811
[end of the periodic table, highest possible atomic number];
news sn(19)mar [lifetimes of unstable elements].
> Online resources:
American Elements website [properties and uses of elements];
The Periodic Table of Videos website.
0: Positronium, Ps
* Idea: An e+e−
bound state; Orthopositronium (spins pointing in the same direction) has
a lifetime of about 150 ns.
* Use: Measuring
the annihilation decay rates provides unique tests of QED.
@ References: Vallery et al PRL(03)
+ pw(03)may [lifetime];
Fleischer et al PRL(06)
+ pn(06)jan [Ps−];
Kiessling a1807 [and electron-positron annihilation];
Gurung et al PRL(20) [spectroscopy, discrepancy with QED].
2: Helium, He > s.a. early-universe
nucleosynthesis; quantum systems; superfluids;
types of superconductors.
* Idea: The second most
abundant element in the universe, but it was only seen in the Sun's
spectrum in 1868, and discovered on Earth (in a uranium mineral) in 1895!
* Isotopes:
8He has been observed, and seems to have a
"halo" of 4 neutrons surrounding a 4He core;
2001, 9He with an extra neutron in a second
outer shell was formed for 10−20
seconds by shooting 11Be nuclei into a
target of 9Be atoms.
* Physical properties:
It is the only substance that won't freeze at absolute zero temperature,
at least at at atmospheric pressure.
* Properties of solid
He-4: At 1 atm, it remains a gas until cooled to 4.2 K, where it
liquefies; Upon further cooling in equilibrium with its vapor, at about
2.2 K the liquid undergoes a spectacular phase transition to a superfluid
state; And due to quantum mechanical zero-point motion, it remains a
liquid upon cooling to as close to absolute zero as physicists have been
able to reach; It solidifies only with the application of some 25 atm of
pressure at very low temperature.
* Supersolid claim:
A confusing, at times frustrating story of claims and disproofs about the
properties of solid 4He; > s.a.
solid matter.
@ General references: Hallock PT(98)jun [3He in 2D];
Chen et al PLB(01) [9He isotope];
news pw(06)oct [universal abundance puzzle];
news pn(08)may [2He observed!];
Lindgren a0810 [fine-structure controversy];
Modarres & Moshfegh PhyA(09) [thermodynamics of normal liquid 3He];
Rieger Phy(12)jun [why doesn't helium solidify at low temperatures?];
> s.a. matter [anti-alpha particles].
@ Related topics: news pt(10)jun [DOE begins rationing 3He];
news pw(12)jul [He molecules in extreme magnetic fields?];
Gasparini Phy(12)
[evidence for a liquid phase in 2D 3He];
McMahon et al RMP(12) [properties under extreme conditions];
Tariq et al PRL(13)
+ Friedrich Phy(13) [fragile LiHe van der Waals molecule];
news wired(15)jul [the trouble with helium availability];
Atiyah MPLA(17)-a1703 [models
of the stable isotopes 4He and 3He];
news pt(20)jun [on He availability].
3: Lithium, Li
> s.a. early-universe nucleosynthesis
and standard cosmological model [7Li problem];
matter near black holes [lithium synthesis].
* Formation: Of all
the elements of the periodic table, lithium has perhaps the most
complicated and mysterious origins; It's the only element that can be
produced in large quantities in three ways: in Big Bang nucleosynthesis
during the first three minutes, in nuclear reactions initiated by cosmic
rays in the interstellar medium, and in stars (evolved low-mass stars,
novae, and supernova explosions), when 3He
and 4He fuse into 7Be,
which undergoes beta decay within tens of days to form 7Li.
@ References: news ab(12)jul [lithium abundance and galactic evolution];
Tajitsu et al Nat(15)mar [evidence for frmation in stars].
4: Beryllium, Be
5: Boron, B
* Properties: It
forms several complex structures that are hard to tell apart; It reacts
with nearly everything, and even a trace of impurities can drastically
change the structure and properties of the boron crystal.
@ References: Eremets et al Sci(01)
+ pw(01)jul [superconductivity at high pressure];
news ns(09)sep [hardness];
news ns(12)jun [boron atoms can form triple bonds and link up in chains].
7: Nitrogen, N
* New forms: 2001,
Non-molecular polymer-like opaque solid with semiconducting properties,
formed around 140 GPa, hysteresis effect makes it stable at atmospheric
p, can store energy.
@ References: Eremets et al Nat(01)may
+ pw(01)may [new form];
Pilyugin et al A&A(03)ap/02,
Chiappini et al A&A(05)ap [origin];
Vangioni et al a1710 [in the interstellar medium].
8: Oxygen, O
> s.a. phase transitions [in solid oxygen].
@ References: Shimizu et al Nat(98)jun [superconducting];
Gorelli et al PRL(99) [O4 molecules at high p];
Freiman & Jodl PRP(04) [solid O].
9: Fluorine, F
@ References: news sci(15)sep [neutrinos created most of the fluorine in the universe].
10: Neon, Ne
11: Sodium, Na
12: Magnesium, Mg
13: Aluminum, Al
14: Silicon, Si
* History: 2001, Japanese
scientists formed Si cage clusters, analogous to C fullerenes [@ Hiura et al
PRL(01)
+ pn(01)feb].
* Use: A vital
material for the semiconductor industry and one of the most studied
elements in all of science.
@ References: news pw(10)aug [melts when cooled];
news sn(11)mar,
ns(12)apr,
pw(12)jun [silicene as the new graphene?];
Taylor PT(16)dec [extreme forms];
news pt(18)feb
[thermal conductivity, ultrapure silicon and isotopic purity].
15: Phosphorus, P
16: Sulfur, S
17: Chlorine, Cl
18: Argon, Ar
19: Potassium, K
20: Calcium, Ca
21: Scandium, Sc
22: Titanium, Ti
23: Vanadium, V
24: Chromium, Cr
25: Manganese, Mn
26: Iron, Fe
@ References: Kuwayama et al PRL(20) [equation of state of liquid Fe under extreme conditions].
27: Cobalt, Co
28: Nickel, Ni
29: Copper, Cu
30: Zinc, Zn > s.a. neutron stars.
31: Gallium, Ga
32: Germanium, Ge
33: Arsenic, As
* Properties: Metalloid.
34: Selenium, Se
* Properties: Non-metal.
35: Bromine, Br
* Properties: Halogen liquid.
36: Krypton, Kr
* Properties: Noble gas.
37: Rubidium, Rb
* Properties: Alkaline metal.
38: Strontium, Sr
* Properties: Alkaline earth metal.
39: Yttrium, Y
* History: Its
discoverer, Johann Gadolin, named it after the Swedish town of Ytterby.
* Properties:
Transition metal; in pure form, silvery-colored, but found in most
rare-earth mineral combinations.
* Use: Make red
phosphors for TV and computer monitors.
40: Zirconium, Zr
* Properties: Transition metal.
@ References: news sn(19)jan [Zr-88 captures neutrons with extreme efficiency].
41: Niobium, Nb
* Comments: Named after
Niobe, daughter of Tantalus; Used in searches for fractional charges.
42: Molybdenum, Mo
* Comments: From the
greek "molybdos", lead; Occurs only in impure forms in nature.
43: Technetium, Tc
* History: The
first element to be synthetically produced, in 1937.
* Where: The only one
of the first 92 elements not found naturally on Earth (except possibly
in minute traces).
* Properties:
Radioactive, but 99Tc has
τ1/2 = 210,000 yr.
* Use: Used in nuclear medicine
for examination of liver and blood, and to identify some stars.
44: Ruthenium, Ru
45: Rhodium, Rh
46: Palladium, Pd
47: Silver, Ag
* Properties: Transition metal.
48: Cadmium, Cd
* Properties: Transition metal.
49: Indium, In
* Properties: Metal.
50: Tin, Sn
@ References: news ea(12)jun [tin-100 is "doubly magic"].
51: Antimony, Sb
52: Tellurium, Te
53: Iodine, I
54: Xenon, Xe
* Where: A noble gas,
present in our atmosphere with concentrations below one part per million.
* Use: For commercial
production, xenon is extracted by liquefying air at low temperature and
high pressure, and then separating the xenon from other components. Its
main use is in various types of lights, including some automobile headlamps,
stroboscopes, and as an exciter in some laser applications.
* Radioactive isotope: Xe-124
has a half-life at about 18 sextillion years, the longest ever directly
measured in a radioactive substance and about 1 trillion times longer
than the age of the universe.
* Puzzle: Our atmosphere
contains far less xenon, relative to the lighter noble gases, than
meteorites similar to the rocky material that formed the Earth.
@ References: news SA(12)oct [the mysterious case of the missing xenon];
news sn(19)apr [rare two-neutrino double electron capture decay of xenon-124 seen].
56: Barium, Ba
57: Lanthanum, La
58: Cerium, Ce
59: Praseodymium, Pr
60: Neodymium, Nd
61: Promethium, Pm
62: Samarium, Sm
63: Europium, Eu
64: Gadolinium, Gd
65: Terbium, Tb
66: Dysprosium, Dy
67: Holmium, Ho
68: Erbium, Er
69: Thulium, Tm
70: Ytterbium, Yb > s.a. bose-einstein condensation.
* Properties:
Has the longest-lived known excited state, 3700 days [@ Roberts et al
PRL(97)].
71: Lutetium, Lu
72: Hafnium, Hf
73: Tantalum, Ta
* Properties:
Ta-180 is the rarest naturally occurring isotope.
74: Tungsten, W
75: Rhenium, Re
76: Osmium, Os
* Properties:
Each atom has eight "valence" electrons available
for covalent bonding, the highest number known.
77: Iridium, Ir
> Online resources:
Wikipedia page.
78: Platinum, Pt
79: Gold, Au
@ References: news CfA(13)jul [Earth's gold came from colliding neutron stars];
news sn(17)jan [measured and calculated ionization energies now agree].
80: Mercury, Hg
81: Thallium, Tl
82: Lead, Pb
@ References: Krygier et al PRL(19)
+ news sn(19)nov [lead becomes stronger than steel under extreme pressures].
83: Bismuth, Bi
84: Polonium, Po
* Properties: The only
element with a simple cubic crystal structure (the result of the complicated
set of orbital energy states of the electrons and their spin-orbit couplings,
made more complicated by the interplay of relativistic effects–specifically
the relativistic increase in electron mass at high velocities); Because of
its crystal structure, its elastic anisotropy is greater than for any other
solid; It has 36 isotopes, more than any other element, and is highly
radioactive; Polonium is a hazardous element that appears in the air and
soil and in such plants as tobacco, tea, and mushrooms.
@ References: news pn(07)jun.
85: Astatine, At
* Properties: It is
the rarest element on Earth (in 1953, Isaac Asimov estimated that the
worldwide total of astatine in nature was 0.07 grams); It is radioactive,
with a half-life of just 8.1 hours.
@ References: news SA(13)may [ionization potential measured at CERN].
86: Radon, Rn
87: Francium, Fr
* Properties: Least
stable of first 103 elements, less than 1 oz exists on Earth at any
time, but not hard to produce.
@ Trapped: news pn(96)may;
PT(96)jun;
Simsarian et al PRL(96).
88: Radium, Ra
89: Actinium, Ac
90: Thorium, Th
91: Protactinium, Pa
92: Uranium, U
@ References: Bernstein a0906 [isotope separation with gas centrifuges].
93: Neptunium, Np
94: Plutonium, Pu
* Properties: One of the
most unusual metals – it's not magnetic and it does not conduct
electricity well; The material also changes its size dramatically with
even the slightest changes in its temperature and pressure; Used as fuel
for nuclear weapons and power plants.
@ References: news pn(07)mar [theory of properties].
95: Americium, Am
96: Curium, Cm
97: Berkelium, Bk
98: Californium, Cf
99: Einsteinium, Es
100: Fermium, Fm
> Online resources:
see Wikipedia page on the Transfermium Wars.
101: Mendelevium, Md
102: Nobelium, No
@ References: news sn(18)jun [shape and structure of the nucleus].
103: Lawrencium, Lr
104: Rutherfordium, Rf
@ References: Wiedenhöver Phy(12)jul [details of the superheavy nucleus' 256Rf
nonspherical shape and internal structure from gamma-ray spectroscopy].
105: Dubnium, Db (Americans had proposed calling it hahnium)
106: Seaborgium, Sg
@ References: Schädel et al Nat(97)jul [chemical properties].
107: Bohrium, Bh
* Properties:
Extremely unstable, and not found in nature; Experiments on chemical
properties done with longer-lived (about 20 sec) isotope at LBL.
108: Hassium, Hs
109: Meitnerium, Mt
110: Darmstadtium, Ds
* History: 1994,
Discovered at the GSI lab in Darmstadt, and quickly seen in other
experiments at Berkeley and the JINR laboratory in Russia – However,
none of the observations confirmed the others because they all produced
different isotopes of the new element; 2003, Confirmed [@ Ginter et al
PRC(03)
+ pw(03)jul].
111: Roentgenium, Rg
* History: 2003, Discovered
at the GSI lab in Darmstadt [news pw(03)oct].
112: Copernicium, Cn
* History: 1996, Discovered
at the GSI lab in Darmstadt, in an experiment in which physicists smashed
zinc atoms into a lead target; This resulted in the production of a single
atom of the new element, with an atomic mass of 277.
* Properties: τ = 280 ms.
@ References: news pn(96)feb [discovery];
Armbruster & Hessberger SA(98)sep [2 atoms of 112 made].
113: Nihonium, Nh (ex "Ununtrium", Uut)
* History: Announced in 2004 by Dubna group
as decay product from #115; Atoms lived up to 1.2 s; 2012, Not yet officially accepted.
@ References: Oganessian et al PRC(04)
+ pw(04)feb;
news nat(12)sep;
news sn(16)nov [name official].
114: Flerovium, Fl (ex "Ununquadium", Uuq)
* History: 1999,
Russian-Livermore discovery, unconfirmed; 2009, Results confirmed
by the LBNL team.
* Properties:
τ = 30 s; Island of stability?
@ References: news pw(99)jan,
PT(99)apr [reported discovery];
Oganessian et al SA(00)jan [island of stability];
Stavsetra PRL(09),
news pt(09)sep,
ns(10)jun,
nyt(11)jun [confirmation].
> Online resources:
see Wikipedia page.
115: Moscovium, Mc (ex "Ununpentium", Uup)
* History: 2004,
Dubna group announcement of the production of 4 atoms, that lived for
about 90 ms; 2011, Discovery not yet officially accepted, but report that
the third atom has been created in Japan; 2013, Discovery confirmed.
@ References: Oganessian et al PRC(04)
+ pw(04)feb;
Rudolph et al PRL(13)
+ news PhysOrg(13)aug [discovery confirmed];
news sn(16)nov [name official].
116: Livermorium, Lv (ex "Ununhexium", Uuh)
* History: 1999,
Discovered at Lawrence Berkeley National Lab, by crashing krypton atoms
into Pb atoms [@ news pn(99)jun,
pn(06)oct,
nyt(11)jun].
> Online resources:
see Wikipedia page.
117: Tennessine, Ts (ex "Ununseptium", Uus)
* History: 2010,
Discovery announced as product of fusion reactions by a collaboration
of Russian and US physicists; 2014, Discovery confirmed.
@ References: Oganessian et al PRL(10) +
Hofmann Phy(10)apr [discovery];
Miller PT(10)jun
[decay gives nine more previously unobserved nuclei];
Oganessian et al PRL(12)
+ Greiner Phy(12);
Scerri SA(13)jun [the periodic table has no gaps, for the first time];
news Phy(14)may [confirmation];
news sn(16)nov [name official].
118: Oganesson, Og (ex "Ununoctium", Uuo)
* History: 1999,
Discovery announced at Lawrence Berkeley National Lab, like #116 [@ news
pn(99)jun,
pw(99)jun];
2001–2002, Discovery retracted after an internal review committee found
that data purporting to show the existence of the new element had been fabricated
[@ news pn(01)aug,
pw(01)aug];
2006, Discovery announced again by JINR-Lawrence Livermore National Lab
collaboration [@ news pn(06)oct,
pw(06)oct].
@ References: Oganessian et al PRL(12)
+ Greiner Phy(12);
Jerabek et al PRL(18)
+ viewpoint + news sn(16)nov [name official];
news pw(18)feb [properties].
119: ?
120: ?
@ References: Smolanczuk PLB(01).
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send feedback and suggestions to bombelli at olemiss.edu – modified 17 aug 2020