Actinium: Difference between revisions
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imported>Philippe Callé m (added history) |
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==History== | ==History== | ||
Actinium has been discovered in 1899 by [[André-Louis Debierne]], and independently by F. Giesel in | Actinium has been discovered in 1899 by [[André-Louis Debierne]], and independently by F. Giesel in 1902This element was named form the greek word ''aktis, aktinos'' (ακτίς, ακτίνος), meaning beam or ray.<ref>David R. Lide, ed., CRC Handbook of Chemistry and Physics, Internet Version 2005, <http://www.hbcpnetbase.com>, CRC Press, Boca Raton, FL, 2005. I.</ref> | ||
and Physics, Internet Version 2005, <http://www.hbcpnetbase.com>, CRC Press, Boca Raton, FL, 2005. I.</ref> | |||
==References== | ==References== | ||
<references/> | <references/> | ||
Revision as of 13:31, 2 April 2011
Actinium is a chemical element, having the chemical symbol Ac.
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Its atomic number (the number of protons) is 89. It has a Standard Atomic Weight of 227, and is typically found as a solid in its elemental form.
Actinium is considered to be a member of the "Transition metal" class of elements, has a boiling point of 3,198 °C, and a melting point of 1,051 °C.
History
Actinium has been discovered in 1899 by André-Louis Debierne, and independently by F. Giesel in 1902This element was named form the greek word aktis, aktinos (ακτίς, ακτίνος), meaning beam or ray.[1]
References
- ↑ David R. Lide, ed., CRC Handbook of Chemistry and Physics, Internet Version 2005, <http://www.hbcpnetbase.com>, CRC Press, Boca Raton, FL, 2005. I.