Problems with radioactive dating methods

He also isolated the first sample of uranium metal by heating uranium tetrachloride with metallic potassium.

problems with radioactive dating methods-56

He then reduced the obtained yellow powder with charcoal, and extracted a black substance that he mistook for metal.

Only 60 years later, the French scientist Eugène-Melchior Péligot identified it as uranium oxide.

Strictly speaking, both actinium and lawrencium have been labeled as group 3 elements, but both elements are often included in any general discussion of the chemistry of the actinide elements.

Actinium is the more often omitted of the two, because its placement as a group 3 element is somewhat more common in texts and for semantic reasons: since "actinide" means "like actinium", it has been argued that actinium cannot logically be an actinide, even though IUPAC acknowledges its inclusion based on common usage.

All but one of the actinides are f-block elements, with the exception being either actinium or lawrencium.

The series mostly corresponds to the filling of the 5f electron shell, although actinium and thorium lack any f-electrons, and curium and lawrencium have the same number as the preceding element.

By reduction of thorium tetrachloride with potassium, he isolated the metal and named it thorium after the Norse god of thunder and lightning Thor.

Actinium was discovered in 1899 by André-Louis Debierne, an assistant of Marie Curie, in the pitchblende waste left after removal of radium and polonium.

The most abundant or easily synthesized actinides are uranium and thorium, followed by plutonium, americium, actinium, protactinium, neptunium, and curium.


  1. This June will mark the second anniversary of the conclusion of the Seven Youth Inquest, and Nishnawbe Aski Nation’s deputy grand chief isn’t satisfied with the progress made on the jury’s 145 recommendations.

  2. Stay true to yourself and your beliefs and everything else will fall into place, but in the meantime, pick yourself up off the ground and keep moving forward.

  3. Cookie] ru stats0ru stats1ru stats2ru pl pl ad. 404. h.#[] adserver. lifemediahouse1. #[Win32/Adware. Win Thirty Two] ads. c1. c3. invitation. by. es. #[Adware. Exploit] logs. ad. ads. adserve. com #[Web Trends] net #[Real Media] Dialer] ads. com clix. Ware. Pharmacy] ads. files. script. b100. b120. b130. b140. b180. banners. dev. srs. stat-counter. #[Backdoor. H] ru ad.100ru ad.120ru ad.120ru traffic. oa. ads. admanager. Cookie] banner. dy. show. openad.tf1#[Real Media] openadext.tf1127.0.0.1 de de de market2. media. www58.#[Web Bug.eluminate] ads. ad. #[Hitbox] oas.#[] w03. idg.#[Web Bug] com com banner. cachebanner. images.top66127.0.0.1 script.top66127.0.0.1 bg ge org banners. d. counter. stats. a. c. cdn. i. cc ads. ads. storage. adserv. ads. dm. ad. pagead. ad. nl. s26. xl. adserver. textad. s3. ads.#[Real Media] cnt. media. media2. advert. cdna. objects.#[] ads. hits3. tracker. origin-tracking. ads. Trust.

  4. Tetraflex is an accomodating multifocal lens not yet available in the US. Hi Supermanr1 Sorry, I haven't answered your questions yet; I've only just seen them.

Comments are closed.