This article is about Aktinum. Actinium was discovered by De Beach in 1899 with the help of Marie Curie.It was found in the remaining pitch blend debris out of the radium and polonium.In 1899, he said that the material was similar to titanium.In 1900, it was similar to thorium.In 1971, there was a debate about whether the discovery of Actinum was right.And in 2000, the announcement was in 1904, and the experiments in 1899–1900 were contradictory.The etymology of Aktis, Aktinos (ακ, ακ), which means light, light, is used in Greek.This metal is not radioactive, but his daughter's nuclear species have radioactive.The similarities between the Lantanum and the Actinum have been gradually revealed.The enemy in nature was an element of the amount.Pure Actinum was only created only in 1950.The Actinum is believed to have been introduced by Victor Gold Schmidt in 1937.
When did De Beach announce the discovery of Actinum?
1904