Actinium is in Group 3 of the periodic table . Its chemical properties are similar to those of lanthanum and of members of the actinide series , of which it is usually considered the first member. It reacts with water to form an insoluble hydroxide with halides to form a trifluoride, trichloride, bromide, or iodide with oxalic acid to form the oxalate with oxygen or sulfur to form the sesquioxide or sesquisulfide.
Actinium was first recognized in 1899 by André Debierne in uranium residues from pitchblende after the radium was extracted by Pierre and Marie Curie . It was later found to be identical with an element discovered in 1902 by Fritz Giesel and which he called emanium.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.
See more Encyclopedia articles on: Compounds and Elements
Browse By Subject
- Earth and the Environment +-
- History +-
- Literature and the Arts +-
- Medicine +-
- People +-
- Philosophy and Religion +-
- Places +-
- Australia and Oceania
- Britain, Ireland, France, and the Low Countries
- Commonwealth of Independent States and the Baltic Nations
- Germany, Scandinavia, and Central Europe
- Latin America and the Caribbean
- Oceans, Continents, and Polar Regions
- Spain, Portugal, Italy, Greece, and the Balkans
- United States, Canada, and Greenland
- Plants and Animals +-
- Science and Technology +-
- Social Sciences and the Law +-
- Sports and Everyday Life +-