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The lanthanides obey the Oddo–Harkins rule – odd-numbered elements are less abundant than their even-numbered neighbors. Three of the lanthanide elements have radioactive isotopes with long half-lives (138 La, 147 Sm and 176 Lu) that can be used to date minerals and rocks from Earth, the Moon and meteorites. [88]
Like the lanthanides, all actinides are highly reactive with halogens and chalcogens; however, the actinides react more easily. Actinides, especially those with a small number of 5f-electrons, are prone to hybridization. This is explained by the similarity of the electron energies at the 5f, 7s and 6d shells. Most actinides exhibit a larger ...
About 40-50% of the actinide contraction has been attributed to relativistic effects. [2] A decrease in atomic radii can be observed across the 5f elements from atomic number 89, actinium, to 102, nobelium. This results in smaller than otherwise expected atomic radii and ionic radii for the subsequent d-block elements starting with 103, lawrencium.
Mayo Clinic is a nonprofit hospital system with campuses in Rochester, Minnesota; Scottsdale and Phoenix, Arizona; and Jacksonville, Florida. [22] [23] Mayo Clinic employs 76,000 people, including more than 7,300 physicians and clinical residents and over 66,000 allied health staff, as of 2022. [5]
Lanthanide metals react exothermically with hydrogen to form LnH 2, dihydrides. [1] With the exception of Eu and Yb, which resemble the Ba and Ca hydrides (non-conducting, transparent salt-like compounds),they form black pyrophoric, conducting compounds [6] where the metal sub-lattice is face centred cubic and the H atoms occupy tetrahedral sites. [1]
Plutonium is a transuranic radioactive chemical element, an actinide metal. Actinide chemistry (or actinoid chemistry) is one of the main branches of nuclear chemistry that investigates the processes and molecular systems of the actinides. The actinides derive their name from the group 3 element actinium.
The Mayo Clinic diet, a program that adheres to this notion, was developed by medical professionals based on scientific research, so you can trust that this program is based on science, and not ...
A low-fiber diet may be used to prepare for or recover from various medical procedures: [1] [2] [4] [5] Abdominal surgery; Colonoscopy; Internal hemorrhoid surgery; A low-fiber diet may also be used during acute stages of the following conditions, to rest the bowels: [1] [2] [4] [5] Bowel inflammation; Crohn's disease; Diverticulitis ...