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Of the 26 "monoisotopic" elements that have only a single stable isotope, all but one have an odd atomic number—the single exception being beryllium. In addition, no odd-numbered element has more than two stable isotopes, while every even-numbered element with stable isotopes, except for helium, beryllium, and carbon, has at least three.
Experiments aimed at synthesizing elements ranging in atomic number from 110 to 127 were conducted at laboratories around the world. [51] [52] These elements were sought in fusion-evaporation reactions, in which a heavy target made of one nuclide is irradiated by accelerated ions of another in a cyclotron, and new nuclides are produced after ...
Lutetium's compounds almost always contain the element in the 3+ oxidation state. [21] Aqueous solutions of most lutetium salts are colorless and form white crystalline solids upon drying, with the common exception of the iodide, which is brown. The soluble salts, such as nitrate, sulfate and acetate form hydrates upon crystallization.
Of the 94 natural elements, eighty have a stable isotope and one more has an almost-stable isotope (with a half-life of 2.01×10 19 years, over a billion times the age of the universe). [ 15 ] [ b ] Two more, thorium and uranium , have isotopes undergoing radioactive decay with a half-life comparable to the age of the Earth .
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 ...
Of the 80 elements with at least one stable isotope, 26 have only one stable isotope. The mean number of stable isotopes for the 80 stable elements is 3.1 stable isotopes per element. The largest number of stable isotopes for a single element is 10 (for tin, element 50).
Elements 121 and 122 should be similar to actinium and thorium respectively. [7] At element 121, the superactinide series is expected to begin, when the 8s electrons and the filling 8p 1/2, 7d 3/2, 6f 5/2, and 5g 7/2 subshells determine the chemistry of these elements.
The island of stability is a hypothetical region in the top right cluster of nuclides that contains isotopes far more stable than other transuranic elements. There are no stable nuclides having an equal number of protons and neutrons in their nuclei with atomic number greater than 20 (i.e. calcium) as can be readily observed from the chart ...