Natural Occurrence of the Elements : Primordial, From decay, Synthetic

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Natural Occurrence of the Elements

In the periodic table there are 3 natural occurrence of the elements : Primordial, From decay and Synthetic.
The first 94 elements occur naturally; the remaining 24, americium to oganesson (95–118), occur only when synthesized in laboratories. Of the 94 naturally occurring elements, 83 are primordial and 11 occur only in decay chains of primordial elements. No element heavier than einsteinium (element 99) has ever been observed in macroscopic quantities in its pure form, nor has astatine (element 85); francium (element 87) has been only photographed in the form of light emitted from microscopic quantities (300,000 atoms).

Natural occurrence of the elements PRIMORDIAL

Primordial nuclides, also known as primordial isotopes, are nuclides found on Earth that have existed in their current form since before Earth was formed. Primordial nuclides were present in the interstellar medium from which the solar system was formed, and were formed in, or after, the Big Bang, by nucleosynthesis in stars and supernovae followed by mass ejection, by cosmic ray spallation, and potentially from other processes. They are the stable nuclides plus the long-lived fraction of radionuclides surviving in the primordial solar nebula through planet accretion until the present. Two hundred and eighty-six such nuclides are known.

List of 34 radioactive primordial nuclides and measured half-lives

These 34 primordial nuclides represent radioisotopes of 28 distinct chemical elements (cadmium, neodymium, samarium, tellurium, uranium, and xenon each have two primordial radioisotopes). The radionuclides are listed in order of stability, with the longest half-life beginning the list. These radionuclides in many cases are so nearly stable that they compete for abundance with stable isotopes of their respective elements. For three chemical elements, indium, tellurium, and rhenium, a very long-lived radioactive primordial nuclide is found in greater abundance than a stable nuclide.

The longest-lived radionuclide has a half-life of 2.2×10²⁴ years, which is 160 trillion times the age of the Universe. Only four of these 34 nuclides have half-lives shorter than, or equal to, the age of the universe. Most of the remaining 30 have half-lives much longer. The shortest-lived primordial isotope, ²³⁵U, has a half-life of 703.8 million years, about one sixth of the age of the Earth and the Solar System.

No.	Nuclide	Energy	Half- life (years)	Decay mode	Decay energy (MeV)	Approx. ratio half-life to age of universe
253	¹²⁸Te	8.743261	2.2×10²⁴	2 β⁻	2.530	160 trillion
254	¹²⁴Xe	8.778264	1.8×10²²	KK	2.864	1 trillion
255	⁷⁸Kr	9.022349	9.2×10²¹	KK	2.846	670 billion
256	¹³⁶Xe	8.706805	2.165×10²¹	2 β⁻	2.462	150 billion
257	⁷⁶Ge	9.034656	1.8×10²¹	2 β⁻	2.039	130 billion
258	¹³⁰Ba	8.742574	1.2×10²¹	KK	2.620	90 billion
259	⁸²Se	9.017596	1.1×10²⁰	2 β⁻	2.995	8 billion
260	¹¹⁶Cd	8.836146	3.102×10¹⁹	2 β⁻	2.809	2 billion
261	⁴⁸Ca	8.992452	2.301×10¹⁹	2 β⁻	4.274, .0058	2 billion
262	²⁰⁹Bi	8.158689	2.01×10¹⁹	α	3.137	1 billion
263	⁹⁶Zr	8.961359	2.0×10¹⁹	2 β⁻	3.4	1 billion
264	¹³⁰Te	8.766578	8.806×10¹⁸	2 β⁻	.868	600 million
265	¹⁵⁰Nd	8.562594	7.905×10¹⁸	2 β⁻	3.367	600 million
266	¹⁰⁰Mo	8.933167	7.804×10¹⁸	2 β⁻	3.035	600 million
267	¹⁵¹Eu	8.565759	5.004×10¹⁸	α	1.9644	300 million
268	¹⁸⁰W	8.347127	1.801×10¹⁸	α	2.509	100 million
269	⁵⁰V	9.055759	1.4×10¹⁷	β⁺ or β⁻	2.205, 1.038	10 million
270	¹¹³Cd	8.859372	7.7×10¹⁵	β⁻	.321	600,000
271	¹⁴⁸Sm	8.607423	7.005×10¹⁵	α	1.986	500,000
272	¹⁴⁴Nd	8.652947	2.292×10¹⁵	α	1.905	200,000
273	¹⁸⁶Os	8.302508	2.002×10¹⁵	α	2.823	100,000
274	¹⁷⁴Hf	8.392287	2.002×10¹⁵	α	2.497	100,000
275	¹¹⁵In	8.849910	4.4×10¹⁴	β⁻	.499	30,000
276	¹⁵²Gd	8.562868	1.1×10¹⁴	α	2.203	8000
277	¹⁹⁰Pt	8.267764	6.5×10¹¹	α	3.252	47
278	¹⁴⁷Sm	8.610593	1.061×10¹¹	α	2.310	7.7
279	¹³⁸La	8.698320	1.021×10¹¹	K or β⁻	1.737, 1.044	7.4
280	⁸⁷Rb	9.043718	4.972×10¹⁰	β⁻	.283	3.6
281	¹⁸⁷Re	8.291732	4.122×10¹⁰	β⁻	.0026	3
282	¹⁷⁶Lu	8.374665	3.764×10¹⁰	β⁻	1.193	2.7
283	²³²Th	7.918533	1.405×10¹⁰	α or SF	4.083	1
284	²³⁸U	7.872551	4.468×10⁹	α or SF or 2 β⁻	4.270	0.3
285	⁴⁰K	8.909707	1.251×10⁹	β⁻ or K or β⁺	1.311, 1.505, 1.505	0.09
286	²³⁵U	7.897198	7.038×10⁸	α or SF	4.679	0.05

Natural occurrence of the elements from DECAY (trace radioisotope)

A trace radioisotope is a radioisotope that occurs naturally in trace amounts (i.e. extremely small). Generally speaking, trace radioisotopes have half-lives that are short in comparison with the age of the Earth, since primordial nuclides tend to occur in larger than trace amounts. Trace radioisotopes are therefore present only because they are continually produced on Earth by natural processes. Natural processes which produce trace radioisotopes include cosmic ray bombardment of stable nuclides, ordinary alpha and beta decay of the long-lived heavy nuclides, thorium-232, uranium-238, and uranium-235, spontaneous fission of uranium-238, and nuclear transmutation reactions induced by natural radioactivity, such as the production of plutonium-239[1] and uranium-236 from neutron capture by natural uranium.

Elements

The elements that occur on Earth only in traces are listed below.

Element name	Chemical Symbol
Technetium	Tc
Promethium	Pm
Polonium	Po
Astatine	At
Radon	Rn
Francium	Fr
Radium	Ra
Actinium	Ac
Protactinium	Pa
Neptunium	Np
Plutonium	Pu

Isotopes of other elements (listnot exhaustive):

Natural occurrence of the elements SYNTHETIC

A synthetic element is one of 24 chemical elements that do not occur naturally on Earth: they have been created by human manipulation of fundamental particles in a nuclear reactor, a particle accelerator, or the explosion of an atomic bomb; thus, they are called “synthetic”, “artificial”, or “man-made”. The synthetic elements are those with atomic numbers 95–118, as shown in purple on the accompanying periodic table: these 24 elements were first created between 1944 and 2010. The mechanism for the creation of a synthetic element is to force additional protons onto the nucleus of an element with an atomic number lower than 95. All synthetic elements are unstable, but they decay at a widely varying rate: their half-lives range from 15.6 million years to a few hundred microseconds.

Five other elements that were created artificially—and thus initially considered to be synthetic—were later discovered to exist in nature in trace quantities. The first, technetium, was created in 1937. Plutonium, atomic number 94, first synthesized in 1940, is another such element. It is the element with the largest number of protons (and equivalent atomic number) to occur in nature, but it does so in such tiny quantities that it is far more practical to synthesize it. Plutonium is extremely well known due to its use in atomic bombs and nuclear reactors. No elements with an atomic number greater than 99 have any uses outside of scientific research, since they have extremely short half-lives, and thus have never been produced in large quantities.

List of synthetic elements

The following elements do not occur naturally on Earth. All are transuranium elements and have atomic numbers of 95 and higher.

Element name	Chemical Symbol	Atomic Number	First definite synthesis
Americium	Am	95	1944
Curium	Cm	96	1944
Berkelium	Bk	97	1949
Californium	Cf	98	1950
Einsteinium	Es	99	1952
Fermium	Fm	100	1952
Mendelevium	Md	101	1955
Nobelium	No	102	1966
Lawrencium	Lr	103	1961
Rutherfordium	Rf	104	1966 (USSR), 1969 (US) *
Dubnium	Db	105	1968 (USSR), 1970 (US) *
Seaborgium	Sg	106	1974
Bohrium	Bh	107	1981
Hassium	Hs	108	1984
Meitnerium	Mt	109	1982
Darmstadtium	Ds	110	1994
Roentgenium	Rg	111	1994
Copernicium	Cn	112	1996
Nihonium	Nh	113	2003–4
Flerovium	Fl	114	1999
Moscovium	Mc	115	2003
Livermorium	Lv	116	2000
Tennessine	Ts	117	2010
Oganesson	Og	118	2002
* Shared credit for discovery.

Other elements usually produced through synthesis

All elements with atomic numbers 1 through 94 occur naturally at least in trace quantities, but the following elements are often produced through synthesis. Technetium, promethium, astatine, neptunium, and plutonium were discovered through synthesis before being found in nature.

Element name	Chemical Symbol	Atomic Number	First definite discovery
Technetium	Tc	43	1937
Promethium	Pm	61	1945
Polonium	Po	84	1898
Astatine	At	85	1940
Francium	Fr	87	1939
Actinium	Ac	89	1902
Protactinium	Pa	91	1913
Neptunium	Np	93	1940
Plutonium	Pu	94	1940

Periodic Table of Elements | Complete List of Chemical Elements by Group, Name, Symbol, Color and Type

Sources: Royal Society of Chemistry, Web MD, Live Science

Photo credit: Wikimedia Commons