Coronium was the name of a suggested

chemical element A chemical element is a chemical substance whose atoms all have the same number of protons. The number of protons is called the atomic number of that element. For example, oxygen has an atomic number of 8: each oxygen atom has 8 protons in its ...

, hypothesised in the 19th century. The name, inspired by the

solar corona In astronomy, a corona (: coronas or coronae) is the outermost layer of a star's Stellar atmosphere, atmosphere. It is a hot but relatively luminosity, dim region of Plasma (physics), plasma populated by intermittent coronal structures such as so ...

, was given by Gruenwald in 1887. A new atomic thin green line in the solar corona was then considered to be emitted by a new element unlike anything else seen under laboratory conditions. It was later determined to be emitted by

iron Iron is a chemical element; it has symbol Fe () and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, forming much of Earth's o ...

(Fe¹³⁺), so highly ionized that it was at that time impossible to produce in a laboratory.

Solar spectroscopy

During the total solar eclipse of 7 August 1869, a green

emission line A spectral line is a weaker or stronger region in an otherwise uniform and continuous spectrum. It may result from emission or absorption of light in a narrow frequency range, compared with the nearby frequencies. Spectral lines are often used ...

of wavelength 530.3 nm was independently observed by

Charles Augustus Young Charles Augustus Young (December 15, 1834 – January 4, 1908) one of the foremost solar spectroscopist astronomers in the United States. He observed solar eclipses and worked on spectroscopy of the Sun. He observed a solar flare with a spe ...

(1834–1908) and William Harkness (1837–1903) in the coronal

spectrum A spectrum (: spectra or spectrums) is a set of related ideas, objects, or properties whose features overlap such that they blend to form a continuum. The word ''spectrum'' was first used scientifically in optics to describe the rainbow of co ...

. Since this line did not correspond to that of any known material, it was proposed that it was due to an unknown element, provisionally named ''coronium''. The supposed element was allegedly discovered also in the gases given off by

Mount Vesuvius Mount Vesuvius ( ) is a Somma volcano, somma–stratovolcano located on the Gulf of Naples in Campania, Italy, about east of Naples and a short distance from the shore. It is one of several volcanoes forming the Campanian volcanic arc. Vesuv ...

in 1898 by a team of Italian chemists led by . Nasini had no photographic record of the spectrum, and the observation was considered unconfirmed. In 1902, over thirty years after his famous predictions of new elements based on his periodic table, and shortly after the discovery of various

noble gases The noble gases (historically the inert gases, sometimes referred to as aerogens) are the members of group 18 of the periodic table: helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), radon (Rn) and, in some cases, oganesson (Og) ...

, the Russian chemist

Dmitri Mendeleev Dmitri Ivanovich Mendeleev ( ; ) was a Russian chemist known for formulating the periodic law and creating a version of the periodic table of elements. He used the periodic law not only to correct the then-accepted properties of some known ele ...

hypothesized that there existed two noble gases of atomic weight less than hydrogen. The first, which he called "element x" or "newtonium", was his attempt at a chemical explanation of the

luminiferous aether Luminiferous aether or ether (''luminiferous'' meaning 'light-bearing') was the postulated Transmission medium, medium for the propagation of light. It was invoked to explain the ability of the apparently wave-based light to propagate through empt ...

. He argued that it had an atomic weight of 0.14. The second, which he called "element y" or coronium, was his attempt to explain the green emission lines from the Sun. He argued that it had an atomic weight of 0.4. It was not until the 1930s that Walter Grotrian and Bengt Edlén discovered that the spectral line at 530.3 nm was due to highly ionized

(Fe¹³⁺); other unusual lines in the coronal spectrum were also caused by highly charged ions, such as

nickel Nickel is a chemical element; it has symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive, but large pieces are slo ...

, the high ionization being due to the extreme temperature of the

. The line at 530.3 nm had previously been misclassified as iron line number 1474.

References

External links

*{{cite web , title=History of Coronium , website=Laser Stars , url=http://laserstars.org/spectra/Coronium.html , access-date=2008-08-25 Misidentified chemical elements Iron

Solar spectroscopy

See also

References

Further reading

External links