Radium
Radium | ||||||||||||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Pronunciation | /ˈreɪdiəm/ | |||||||||||||||||||||||||||||||||||
Appearance | silvery white metallic | |||||||||||||||||||||||||||||||||||
Mass number | [226] | |||||||||||||||||||||||||||||||||||
Radium in the periodic table | ||||||||||||||||||||||||||||||||||||
| ||||||||||||||||||||||||||||||||||||
kJ/mol | ||||||||||||||||||||||||||||||||||||
Heat of vaporization | 113 kJ/mol | |||||||||||||||||||||||||||||||||||
Vapor pressure
| ||||||||||||||||||||||||||||||||||||
Atomic properties | ||||||||||||||||||||||||||||||||||||
Discovery | Pierre and Marie Curie (1898) | |||||||||||||||||||||||||||||||||||
First isolation | Marie Curie (1910) | |||||||||||||||||||||||||||||||||||
Isotopes of radium | ||||||||||||||||||||||||||||||||||||
| ||||||||||||||||||||||||||||||||||||
Radium is a
Radium, in the form of
In nature, radium is found in
Bulk properties
Radium is the heaviest known
Pure radium is a
Isotopes
Radium has 33 known isotopes, with
In the early history of the study of radioactivity, the different natural isotopes of radium were given different names. In this scheme, 223Ra was named actinium X (AcX), 224Ra thorium X (ThX), 226Ra radium (Ra), and 228Ra mesothorium 1 (MsTh1).[4](p 3) When it was realized that all of these are isotopes of the same element, many of these names fell out of use, and "radium" came to refer to all isotopes, not just 226Ra. Some of radium-226's decay products received historical names including "radium", ranging from radium A to radium G, with the letter indicating approximately how far they were down the chain from their parent 226Ra: Radium emanation = 222Rn, Ra A = 218Po, Ra B = 214Pb, Ra C = 214Bi, Ra C1 = 214Po, Ra C2 = 210Tl, Ra D = 210Pb, Ra E = 210Bi, Ra F = 210Po, and Ra G = 206Pb .[12]
226Ra is the most stable isotope of radium and is the last isotope in the (4n + 2) decay chain of uranium-238 with a half-life of over a millennium: it makes up almost all of natural radium. Its immediate decay product is the dense radioactive noble gas radon (specifically the isotope 222Rn), which is responsible for much of the danger of environmental radium.[13] It is 2.7 million times more radioactive than the same molar amount of natural uranium (mostly uranium-238), due to its proportionally shorter half-life.[14][15]
A sample of radium metal maintains itself at a higher
In 2013, it was discovered at CERN that the nucleus of radium-224 is pear-shaped using a technique called coulomb excitation. This was the first discovery of an asymmetric nucleus.[17] This is a strong circumstantial evidence that certain heavy, unstable atomic nuclei have distorted nuclei, in this case, a pear shape.[18]
Chemistry
Radium, like barium, is a highly
Compounds
Solid radium compounds are white as radium ions provide no specific coloring, but they gradually turn yellow and then dark over time due to self-radiolysis from radium's alpha decay.[4](p 4) Insoluble radium compounds coprecipitate with all barium, most strontium, and most lead compounds.[4](p 8)
Radium bromide (RaBr2) is also a colorless, luminous compound.[4](pp 4–8) In water, it is more soluble than radium chloride. Like radium chloride, crystallization from aqueous solution gives the dihydrate RaBr2·2H2O, isomorphous with its barium analog. The ionizing radiation emitted by radium bromide excites nitrogen molecules in the air, making it glow. The alpha particles emitted by radium quickly gain two electrons to become neutral helium, which builds up inside and weakens radium bromide crystals. This effect sometimes causes the crystals to break or even explode.[4](pp 4–8)
Radium nitrate (Ra(NO3)2) is a white compound that can be made by dissolving radium carbonate in nitric acid. As the concentration of nitric acid increases, the solubility of radium nitrate decreases, an important property for the chemical purification of radium.[4](pp 4–8)
Radium forms much the same insoluble salts as its lighter congener barium: it forms the insoluble
Occurrence
All isotopes of radium have half-lives much shorter than the
History
Radium was
In September 1910, Marie Curie and André-Louis Debierne announced that they had isolated radium as a pure metal through the electrolysis of pure radium chloride (RaCl2) solution using a mercury cathode, producing radium–mercury amalgam.[29] This amalgam was then heated in an atmosphere of hydrogen gas to remove the mercury, leaving pure radium metal.[30] Later that same year, E. Eoler isolated radium by
The general historical unit for radioactivity, the curie, is based on the radioactivity of 226Ra: it was originally defined as the radioactivity of one gram of radium-226,[32] but the definition was later slightly refined to be 3.7×1010 disintegrations per second.
Historical applications
Luminescent paint
Radium was formerly used in self-luminous paints for watches, nuclear panels, aircraft switches, clocks, and instrument dials. A typical self-luminous watch that uses radium paint contains around 1 microgram of radium.[33] In the mid-1920s, a lawsuit was filed against the United States Radium Corporation by five dying "Radium Girls" – dial painters who had painted radium-based luminous paint on the dials of watches and clocks. The dial painters were instructed to lick their brushes to give them a fine point, thereby ingesting radium.[34] Their exposure to radium caused serious health effects which included sores,
During the litigation, it was determined that the company's scientists and management had taken considerable precautions to protect themselves from the effects of radiation, but it did not seem to protect their employees. Additionally, for several years the companies had attempted to cover up the effects and avoid liability by insisting that the Radium Girls were instead suffering from
As a result of the lawsuit, the adverse effects of radioactivity became widely known, and radium-dial painters were instructed in proper safety precautions and provided with protective gear. In particular, dial painters no longer licked paint brushes to shape them (which caused some ingestion of radium salts). Radium was still used in dials as late as the 1960s, but there were no further injuries to dial painters. This highlighted that the harm to the Radium Girls could easily have been avoided.[36]
From the 1960s the use of radium paint was discontinued. In many cases luminous dials were implemented with non-radioactive fluorescent materials excited by light; such devices glow in the dark after exposure to light, but the glow fades.
Clocks, watches, and instruments dating from the first half of the 20th century, often in military applications, may have been painted with radioactive luminous paint. They are usually no longer luminous; however, this is not due to radioactive decay of the radium (which has a half-life of 1600 years) but to the fluorescence of the zinc sulfide fluorescent medium being worn out by the radiation from the radium.[42] The appearance of an often thick layer of green or yellowish brown paint in devices from this period suggests a radioactive hazard. The radiation dose from an intact device is relatively low and usually not an acute risk; but the paint is dangerous if released and inhaled or ingested.[5][43]
Commercial use
Radium was once an additive in products such as toothpaste, hair creams, and even food items due to its supposed curative powers.
Medical use
Radium (usually in the form of radium chloride or radium bromide) was used in medicine to produce radon gas, which in turn was used as a cancer treatment; for example, several of these radon sources were used in Canada in the 1920s and 1930s.[5][46] However, many treatments that were used in the early 1900s are not used anymore because of the harmful effects radium bromide exposure caused. Some examples of these effects are
Early in the 1900s, biologists used radium to induce mutations and study genetics. As early as 1904, Daniel MacDougal used radium in an attempt to determine whether it could provoke sudden large mutations and cause major evolutionary shifts. Thomas Hunt Morgan used radium to induce changes resulting in white-eyed fruit flies. Nobel-winning biologist Hermann Muller briefly studied the effects of radium on fruit fly mutations before turning to more affordable x-ray experiments.[48]
Howard Atwood Kelly, one of the founding physicians of Johns Hopkins Hospital, was a major pioneer in the medical use of radium to treat cancer.[49] His first patient was his own aunt in 1904, who died shortly after surgery.[50] Kelly was known to use excessive amounts of radium to treat various cancers and tumors. As a result, some of his patients died from radium exposure.[51] His method of radium application was inserting a radium capsule near the affected area, then sewing the radium "points" directly to the
Production
Uranium had no large scale application in the late 19th century and therefore no large uranium mines existed. In the beginning the only large source for uranium ore was the
In the first extraction of radium, Curie used the residues after extraction of uranium from pitchblende. The uranium had been extracted by dissolution in
After the isolation of radium by Marie and Pierre Curie from uranium ore from Jáchymov, several scientists started to isolate radium in small quantities. Later, small companies purchased mine tailings from Jáchymov mines and started isolating radium. In 1904, the Austrian government nationalised the mines and stopped exporting raw ore. Until 1912 when radium production increased, radium availability was low.[53]
The formation of an Austrian monopoly and the strong urge of other countries to have access to radium led to a worldwide search for uranium ores. The United States took over as leading producer in the early 1910s. The Carnotite sands in Colorado provide some of the element, but richer ores are found in the Congo and the area of the Great Bear Lake and the Great Slave Lake of northwestern Canada. Neither of the deposits is mined for radium but the uranium content makes mining profitable.[23][55]
The Curies' process was still used for industrial radium extraction in 1940, but mixed bromides were then used for the fractionation. If the barium content of the uranium ore is not high enough it is easy to add some to carry the radium. These processes were applied to high grade uranium ores but may not work well with low grade ores.[56]
Small amounts of radium were still extracted from uranium ore by this method of mixed precipitation and ion exchange as late as the 1990s,[3](pp 109–110) but as of 2011, they are extracted only from spent nuclear fuel.[42](p437) In 1954, the total worldwide supply of purified radium amounted to about 5 pounds (2.3 kg)[33] and it is still in this range in 2015, while the annual production of pure radium compounds is only about 100 g in total as of 1984.[3](pp 109–110) The chief radium-producing countries are Belgium, Canada, the Czech Republic, Slovakia, the United Kingdom, and Russia.[3](pp 109–110) The amounts of radium produced were and are always relatively small; for example, in 1918, 13.6 g of radium were produced in the United States.[57] The metal is isolated by reducing radium oxide with aluminium metal in a vacuum at 1,200 °C.[20]
Modern applications
Radium is seeing increasing use in the field of atomic, molecular, and optical physics. Symmetry breaking forces scale proportional to
Radium is also a promising candidate for trapped ion optical clocks. The radium ion has two subhertz-linewidth transitions from the ground state that could serve as the clock transition in an optical clock.[63] A 226Ra+ trapped ion atomic clock has been demonstrated on the to transition.[64] Additionally, radium is particularly well suited for a transportable optical clock as all transitions necessary for clock operation can be addressed with direct diode lasers at common wavelengths.
Some of the few practical uses of radium are derived from its radioactive properties. More recently discovered
The isotope 223Ra (the chloride is under the trade name
Radium is still used in 2007 as a radiation source in some
Hazards
Radium is highly radioactive, as is its immediate decay product,
Some of the biological effects of radium include the first case of "radium-dermatitis", reported in 1900, two years after the element's discovery. The French physicist
As of 2015[update], 226Ra is considered to be the most toxic of the quantity radioelements, and it must be handled in tight glove boxes with significant airstream circulation that is then treated to avoid escape of its daughter 222Rn to the environment. Old ampoules containing radium solutions must be opened with care because radiolytic decomposition of water can produce an overpressure of hydrogen and oxygen gas.[20] The world's largest concentration of 226Ra is stored within the Interim Waste Containment Structure, approximately 9.6 mi (15.4 km) north of Niagara Falls, New York.[77] The Maximum Contaminant Level (MCL) for radium is 5pCi/L for drinking water, however, the OSHA does not set an exposure limit, as there is a radiation limit already set up.[78]
See also
Notes
References
- ^ .
- ^ "Radium". Elements / Periodic Table. rsc.org. Royal Society of Chemistry. Archived from the original on 24 March 2016. Retrieved 5 July 2016.
- ^ a b c d e f g h
ISBN 978-0-08-037941-8. - ^ a b c d e f g h i j k l m n o p q r s t
Kirby, H.W. & Salutsky, Murrell L. (December 1964b). The Radiochemistry of Radium (Report). crediting UNT Libraries Government Documents Department – via University of North Texas, UNT Digital Library.- alternate source
- ^ a b c "Radium". Encyclopædia Britannica. Archived from the original on 15 June 2013.
- ^
Lide, D.R.; et al., eds. (2004). CRC Handbook of Chemistry and Physics (84th ed.). Boca Raton, FL: CRC Press. ISBN 978-0-8493-0484-2.
- ^
Weigel, F.; Trinkl, A. (1968). "Zur Kristallchemie des Radiums" [On radium's chemical chrystalography]. Radiochim. Acta (in German). 10 (1–2): 78. S2CID 100313675.
- ^ a b
Young, David A. (1991). "Radium". Phase Diagrams of the Elements. University of California Press. p. 85. ISBN 978-0-520-91148-2.
- ^ "Crystal structures of the chemical elements at 1 bar". uni-bielefeld.de. Archived from the original on 26 August 2014.
- ^ Peppard, D.F.; Mason, G.W.; Gray, P.R.; Mech, J.F (1952). "Occurrence of the (4n + 1) series in nature". from the original on 28 July 2019. Retrieved 6 July 2019.
- .
- ^
Kuhn, W. (1929). "LXVIII. Scattering of thorium C" γ-radiation by radium G and ordinary lead". The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science. 8 (52): 628. ISSN 1941-5982.
- ^ a b c d e f g h
Radiation protection. Radium. epa.gov (Report). Radiation / Radionuclides. United States Environmental Protection Agency. Archived from the original on 11 February 2015. - ^
Soddy, Frederick (25 August 2004). The Interpretation of Radium. Courier Corporation. p. 139 ff. ISBN 978-0-486-43877-1. Archivedfrom the original on 5 September 2015. Retrieved 27 June 2015 – via Google Books.
- ^
Malley, Marjorie C. (2011). Radioactivity. Oxford University Press. p. 115 ff. ISBN 978-0-19-983178-4. Retrieved 27 June 2015 – via Internet Archive (archive.org).
- ISBN 978-0-486-43875-7. Archivedfrom the original on 5 September 2015. Retrieved 27 June 2015.
- ^ "First observations of short-lived pear-shaped atomic nuclei – CERN". home.cern. Archived from the original on 12 June 2018. Retrieved 8 June 2018.
- S2CID 4380776.
- ISBN 978-1-4020-9974-8.
- ^ a b c d e f
Keller, Cornelius; Wolf, Walter; Shani, Jashovam. "Radionuclides, 2. Radioactive Elements and Artificial Radionuclides".ISBN 978-3527306732. - ^ "Radium" Archived 15 November 2012 at the Wayback Machine, Los Alamos National Laboratory. Retrieved 5 August 2009.
- ^ Section 14, Geophysics, Astronomy, and Acoustics; Abundance of Elements in the Earth's Crust and in the Sea, in Lide, David R. (ed.), CRC Handbook of Chemistry and Physics, 85th Edition. CRC Press. Boca Raton, Florida (2005).
- ^ ISBN 1-4398-5511-0.
- ^ Curie, Pierre; Curie, Marie & Bémont, Gustave (1898). "Sur une nouvelle substance fortement radio-active, contenue dans la pechblende (On a new, strongly radioactive substance contained in pitchblende)". Comptes Rendus. 127: 1215–1217. Archived from the original on 6 August 2009. Retrieved 1 August 2009.
- doi:10.1021/ed010p79.
- .
- ISBN 978-3-642-22121-7.
- doi:10.1021/ed010p79.
- ^ Frank Moore Colby; Allen Leon Churchill (1911). New International Yearbook: A Compendium of the World's Progress. Dodd, Mead and Co. p. 152 ff.
- ^ Curie, Marie & Debierne, André (1910). "Sur le radium métallique" [On metallic radium]. Comptes Rendus (in French). 151: 523–525. Archived from the original on 20 July 2011. Retrieved 1 August 2009.
- ISBN 978-0-7923-4769-9. Archivedfrom the original on 5 September 2015. Retrieved 27 June 2015.
- ^
Frame, Paul W. (October–November 1996). "How the Curie came to be". Health Physics Society Newsletter. Archived from the original on 20 March 2012. Retrieved 9 May 2023 – via Oak Ridge Associated Universities (orau.org).
{{cite magazine}}
: CS1 maint: unfit URL (link) - ^ a b
Terrill, J.G. Jr.; Ingraham, S.C., 2nd; Moeller, D.W. (1954). "Radium in the healing arts and in industry: Radiation exposure in the United States". Public Health Reports. 69 (3): 255–262. PMID 13134440.)
{{cite journal}}
: CS1 maint: multiple names: authors list (link) CS1 maint: numeric names: authors list (link - ^ Frame, Paul (1999). "Radioluminescent paint". Museum of Radiation and Radioactivity. Oak Ridge Associated Universities. Archived from the original on 31 July 2014.
- ^ "Environmental history timeline – Radium Girls". 20 July 2012. Archived from the original on 2 September 2018. Retrieved 1 September 2018.
- ^ Rowland, R. E. (1995) Radium in humans: a review of U.S. studies Archived 9 November 2011 at the Wayback Machine. Argonne National Laboratory. p. 22
- ISBN 978-1-4020-1860-2.
- ^ Lavrukhina, Avgusta Konstantinovna; Pozdnyakov, Aleksandr Aleksandrovich (1966). Аналитическая химия технеция, прометия, астатина и франция [Analytical Chemistry of Technetium, Promethium, Astatine, and Francium] (in Russian). Nauka. p. 118.
- .
- ^ Hydrogen-3 (PDF) (Report). Nuclide safety data sheet. Environmenal Health & Safety Office, Emory University. Archived from the original (PDF) on 20 May 2013 – via ehso.emory.edu.
- ^ Zerriffi, Hisham (January 1996). "Tritium: The environmental, health, budgetary, and strategic effects of the Department of Energy's decision to produce tritium". Institute for Energy and Environmental Research. Archived from the original on 13 July 2010. Retrieved 15 September 2010.
- ^ a b c d
Emsley, John (2003). Nature's building blocks: an A-Z guide to the elements. Oxford University Press. p. 351 ff.ISBN 978-0-19-850340-8. Retrieved 27 June 2015. - ^ "Luminous radium paint". vintagewatchstraps.com. Archived from the original on 4 March 2013.
- ^ "French Web site featuring products (medicines, mineral water, even underwear) containing radium". Archived from the original on 15 March 2011. Retrieved 1 August 2009.
- ^ Cherbonnier, Alice (1 October 1997). "Nasal radium irradiation of children has health fallout". Baltimore Chronicle. Archived from the original on 28 September 2011. Retrieved 1 August 2009.
- ^
Hayter, Charles (2005). "The politics of radon therapy in the 1930s". An Element of Hope: Radium and the response to cancer in Canada, 1900–1940. McGill-Queen's Press. ISBN 978-0-7735-2869-7– via Google Books.
- PMID 10589294.
- ^ Hamilton, Vivien (2016). "The Secrets of Life: Historian Luis Campos resurrects radium's role in early genetics research". Distillations. 2 (2): 44–45. Archived from the original on 23 March 2018. Retrieved 22 March 2018.
- ^ "The Four Founding Physicians". About / History. Hopkins Medicine (hopkinsmedicine.org). Johns Hopkins School of Medicine, Johns Hopkins University. Archived from the original on 10 March 2015. Retrieved 10 April 2013.
- ^
Dastur, Adi E.; Tank, P.D. (2011). "Howard Atwood Kelly: Much beyond the stitch". The Journal of Obstetrics and Gynecology of India. 60 (5): 392–394. PMC 3394615.
- ^ a b
Aronowitz, Jesse N.; Robison, Roger F. (2010). "Howard Kelly establishes gynecologic brachytherapy in the United States". Brachytherapy. 9 (2): 178–184. PMID 20022564.
- ^
Skloot, Rebecca (2 February 2010). The Immortal Life of Henrietta Lacks. Random House Digital. ISBN 978-0-307-58938-5. Archivedfrom the original on 17 June 2013. Retrieved 8 April 2013.
- ^ .
- ^ "Lateral Science" Archived 2 April 2015 at the Wayback Machine. lateralscience.blogspot.se. November 2012
- JSTOR 40796935.
- .
- PMID 17809659.
- S2CID 250910046– via Institute of Physics.
- – via aapt.scitation.org (Atypon).
- ^
Dobaczewski, J.; Engel, J. (13 June 2005). "Nuclear Time-Reversal Violation and the Schiff Moment of $^{225}\mathrm{Ra}$". S2CID 328830– via APS.org.
- ^
Graner, B.; Chen, Y.; Lindahl, E.G.; Heckel, B.R. (18 April 2016). "Reduced limit on the permanent electric dipole moment of 199Hg". Physical Review Letters. 116 (16): 161601. S2CID 2230011– via APS.org.
- ^
Parker, R.H.; Dietrich, M.R.; Kalita, M.R.; Lemke, N.D.; Bailey, K.G.; Bishof, M.; et al. (9 June 2015). "First measurement of the atomic electric dipole moment of 225Ra". S2CID 41982867– via APS.org.
- S2CID 119948902– via Springer Link.
- S2CID 246035333– via APS.
- ^
Radiation Source Use and Replacement: Abbreviated version (Report). Committee on Radiation Source Use and Replacement / Nuclear and Radiation Studies Board. Washington, DC: U.S. National Research Council / National Academies Press. January 2008. p. 24. ISBN 978-0-309-11014-3. Archivedfrom the original on 5 September 2015. Retrieved 27 June 2015 – via Google Books.
- ^
Bentel, Gunilla Carleson (1996). Radiation therapy planning. McGraw Hill Professional. p. 8. ISBN 978-0-07-005115-7. Archivedfrom the original on 5 September 2015. Retrieved 27 June 2015 – via Google Books.
- ^ "Xofigo US Patent". Xofigo. Retrieved 28 September 2022.
- ^ "FDA OKs pinpoint prostate cancer radiation drug Xofigo from Bayer, Algeta". Archived from the original on 28 June 2013. Retrieved 1 October 2014.
- ^ "FDA approves Xofigo for advanced prostate cancer". cancer.org. 15 May 2013. Archived from the original on 6 July 2013.
- ^
Maffioli, L.; Florimonte, L.; Costa, D.C.; Correia Castanheira, J.; Grana, C.; Luster, M.; et al. (2015). "New radiopharmaceutical agents for the treatment of castration-resistant prostate cancer". Q J Nucl Med Mol Imaging. 59 (4): 420–438. PMID 26222274.
- ISBN 978-3-527-31097-5.
- ISBN 978-0-444-52715-8.
- ^ Holden, N.E.; Reciniello, R.N.; Hu, J.P.; Rorer, David C. (2004). "Radiation dosimetry of a graphite moderated radium-beryllium source" (PDF). Health Physics. 86 (5 Supplement): S110–S112. (PDF) from the original on 23 July 2018. Retrieved 25 October 2017.
- ^
Weisgall, Jonathan M. (1994). Operation Crossroads: The atomic tests at Bikini Atoll. Naval Institute Press. p. 238. ISBN 978-1-55750-919-2. Retrieved 20 August 2011.
- ^
Fry, Shirley A. (1998). "Supplement: Madame Curie's discovery of radium (1898): A commemoration by women in radiation sciences". Radiation Research. 150 (5): S21–S29. PMID 9806606.
- ^
Redniss, Lauren (2011). Radioactive: Marie & Pierre Curie: A tale of love and fallout. New York, NY: HarperCollins. p. 70. ISBN 978-0-06-135132-7.
- . (subscription required)
- ^
EPA Facts about Radium (PDF). semspub.epa.gov (Report). U.S. Environmental Protection Agency. Retrieved 6 March 2023.
Bibliography
- ISBN 978-0-08-037941-8.
Further reading
- Stwertka, Albert (1998). Guide to the Elements (revised ed.). Oxford University Press. ISBN 978-0-19-508083-4.
- Grady, Denise (6 October 1998). "A Glow in the Dark, and a Lesson in Scientific Peril". The New York Times. Retrieved 25 December 2007.
- Nanny Fröman (1 December 1996). "Marie and Pierre Curie and the discovery of polonium and radium". Nobel Foundation. Retrieved 25 December 2007.
- Macklis, R.M. (1993). "The great radium scandal". PMID 8351514.
- Clark, Claudia (1987). Radium Girls: Women and industrial health reform, 1910–1935. University of North Carolina Press. ISBN 978-0-8078-4640-7.
- Wikidata Q22920166
- Santos, Lucy Jane (2020). Half Lives: The Unlikely History of Radium. Icon Books. OCLC 1158229829.
External links
- "The discovery of radium". Lateral Science. UK. 8 July 2012. Archived from the original on 9 March 2016. Retrieved 13 May 2017.
- Radium water bath in Oklahoma. markwshead.com (photographic images).
- "Radium, radioactive". NLM Hazardous Substances Databank. U.S. National Institutes of Health.
- "Annotated bibliography for radium". Alsos Digital Library for Nuclear Issues. Lexington, VA: Washington and Lee University. Archived from the original on 25 June 2019.
- "Radium". The Periodic Table of Videos. University of Nottingham.