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The transuranium (or transuranic) elements are the chemical elements with atomic number greater than 92, which is the atomic number of uranium.All of them are radioactively unstable and decay into other elements.
The adoption of the term "nucleus" to atomic theory, however, was not immediate. In 1916, for example, Gilbert N. Lewis stated, in his famous article The Atom and the Molecule, that "the atom is composed of the kernel and an outer atom or shell." [12] Similarly, the term kern meaning kernel is used for nucleus in German and Dutch.
A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Uranium radioactively decays, usually by emitting an alpha particle. The half-life of this decay varies between 159,200 and 4.5 billion years for different isotopes, making them useful for dating the age of the Earth.
Nuclear binding energy, the energy required to split a nucleus of an atom. Nuclear potential energy , the potential energy of the particles inside an atomic nucleus. Nuclear reaction , a process in which nuclei or nuclear particles interact, resulting in products different from the initial ones; see also nuclear fission and nuclear fusion .
The two types of beta decay are known as beta minus and beta plus.In beta minus (β −) decay, a neutron is converted to a proton, and the process creates an electron and an electron antineutrino; while in beta plus (β +) decay, a proton is converted to a neutron and the process creates a positron and an electron neutrino. β + decay is also known as positron emission.
A nuclide is a species of an atom with a specific number of protons and neutrons in the nucleus, for example, carbon-13 with 6 protons and 7 neutrons. The nuclide concept (referring to individual nuclear species) emphasizes nuclear properties over chemical properties, whereas the isotope concept (grouping all atoms of each element) emphasizes chemical over nuclear.
The nuclear shell model is partly analogous to the atomic shell model, which describes the arrangement of electrons in an atom, in that a filled shell results in better stability. When adding nucleons ( protons and neutrons ) to a nucleus, there are certain points where the binding energy of the next nucleon is significantly less than the last one.
A carbon-13 label was used to determine the mechanism in the 1,2- to 1,3-didehydrobenzene conversion of the phenyl substituted aryne precursor 1 to acenaphthylene. [3]An isotopic tracer, (also "isotopic marker" or "isotopic label"), is used in chemistry and biochemistry to help understand chemical reactions and interactions.