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This page lists radioactive nuclides by their half-life.
The darker more stable isotope region departs from the line of protons (Z) = neutrons (N), as the element number Z becomes larger. This is a list of chemical elements by the stability of their isotopes. Of the first 82 elements in the periodic table, 80 have isotopes considered to be stable. [1] Overall, there are 251 known stable isotopes in ...
A chemical element, often simply called an element, is a type of atom which has a specific number of protons in its atomic nucleus (i.e., a specific atomic number, or Z). [ 1 ] The definitive visualisation of all 118 elements is the periodic table of the elements , whose history along the principles of the periodic law was one of the founding ...
They considered elements 158 through 164 to be homologues of groups 4 through 10, and not 6 through 12, noting similarities of electron configurations to the period 5 transition metals (e.g. element 159 7d 4 9s 1 vs Nb 4d 4 5s 1, element 160 7d 5 9s 1 vs Mo 4d 5 5s 1, element 162 7d 7 9s 1 vs Ru 4d 7 5s 1, element 163 7d 8 9s 1 vs Rh 4d 8 5s 1 ...
Periodic table of the chemical elements showing the most or more commonly named sets of elements (in periodic tables), and a traditional dividing line between metals and nonmetals. The f-block actually fits between groups 2 and 3; it is usually shown at the foot of the table to save horizontal space.
Charles Hatchett named element 41 columbium in 1801 [4] (Cb), [5] but after the publication of On the Identity of Columbium and Tantalum by William Hyde Wollaston in 1809, the claims of discovery of Hatchett were mistakenly considered refuted. [6] In 1846, Heinrich Rose discovered that tantalite contained an element similar to tantalum and ...
The metallic elements in the periodic table located between the transition metals to their left and the chemically weak nonmetallic metalloids to their right have received many names in the literature, such as post-transition metals, poor metals, other metals, p-block metals, basic metals, and chemically weak metals.
The synthetic elements are those with atomic numbers 95–118, as shown in purple on the accompanying periodic table: [1] these 24 elements were first created between 1944 and 2010. The mechanism for the creation of a synthetic element is to force additional protons into the nucleus of an element with an atomic number lower than 95.