Information about Atomic Number
See also: List of elements by atomic number
In chemistry and physics, the atomic number (also known as the proton number) is the number of protons found in the nucleus of an atom. It is traditionally represented by the symbol Z. The atomic number uniquely identifies a chemical element. In an atom of neutral charge, the number of electrons also equals the atomic number.
The atomic number is closely related to the mass number, which is the number of protons and neutrons in the nucleus of an atom. The mass number defines the isotope of the element and often comes after the name of the element, e.g. carbon-14 (used in carbon dating).
The anomalies in this sequence were finally explained after research by Henry Gwyn Jeffreys Moseley in 1913[3]. Moseley discovered a strict relationship between the x-ray diffraction spectra of elements, and their correct location in the periodic table. This led to the conclusion that the atomic number corresponds to the electric charge of the nucleus — the charge of the protons. The atomic number is the number of protons that is equal to the number of electrons.
The periodic table of the chemical elements is a tabular method of displaying the chemical elements. Although precursors to this table exist, its invention is generally credited to Russian chemist Dmitri Mendeleev in 1869.
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In chemistry and physics, the atomic number (also known as the proton number) is the number of protons found in the nucleus of an atom. It is traditionally represented by the symbol Z. The atomic number uniquely identifies a chemical element. In an atom of neutral charge, the number of electrons also equals the atomic number.
The atomic number is closely related to the mass number, which is the number of protons and neutrons in the nucleus of an atom. The mass number defines the isotope of the element and often comes after the name of the element, e.g. carbon-14 (used in carbon dating).
History
The atomic number originally meant the number of an element's place in the periodic table. Dmitri Mendeleev arranged the known elements in increasing order of atomic weight and grouped by their similar chemical properties[1]. However, placing the elements in strict order of atomic weight resulted in some mismatches. Iodine and tellurium, if listed by atomic weight, appeared to be in the wrong order; and would fit better by chemical properties if their places in the table were swapped[2]. Placing them in the order which fit their properties most closely, their number in the table was their atomic number. This number appeared to be related to the mass of the atom but, as the discrepancy showed, reflected some property other than mass.The anomalies in this sequence were finally explained after research by Henry Gwyn Jeffreys Moseley in 1913[3]. Moseley discovered a strict relationship between the x-ray diffraction spectra of elements, and their correct location in the periodic table. This led to the conclusion that the atomic number corresponds to the electric charge of the nucleus — the charge of the protons. The atomic number is the number of protons that is equal to the number of electrons.
Chemical properties
Each element has a specific set of chemical properties as a consequence of the number of protons in its nucleus. The charge of an atom's nucleus defines its electron configuration based on principles of quantum mechanics. The form of each element's electron shells, particularly the valence shell, is the primary factor in determining its chemical bonding behavior.New elements
The quest for new elements is usually described using atomic number. As of early 2007, elements with atomic numbers through 118 (excluding 117) have been discovered. Synthesis of new elements is accomplished by bombarding target atoms of heavy elements with ions, such that the sum of the atomic numbers of the target and ion elements equals the atomic number of the element being created. In general, the half-life becomes shorter as atomic number increases, though an "island of stability" may exist for undiscovered isotopes with certain numbers of protons and neutrons.See also
Notes
1. ^ The Periodic Table of Elements (American Institute of Physics)
2. ^ The Development of the Periodic Table (Chemsoc)
3. ^ Ordering the Elements in the Periodic Table (Chemsoc)
2. ^ The Development of the Periodic Table (Chemsoc)
3. ^ Ordering the Elements in the Periodic Table (Chemsoc)
A table of chemical elements ordered by atomic number and color coded according to type of element. Given is each element's name, element symbol, group and period, Chemical series, and atomic mass (or most stable isotope).
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Physics is the science of matter[1] and its motion[2][3], as well as space and time[4][5] —the science that deals with concepts such as force, energy, mass, and charge.
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Proton
The quark structure of the proton.
Composition: 2 up, 1 down
Family: Fermion
Group: Quark
Interaction: Gravity, Electromagnetic, Weak, Strong
Antiparticle: Antiproton
Discovered: Ernest Rutherford (1919)
Symbol: p+
Mass: 1.
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The quark structure of the proton.
Composition: 2 up, 1 down
Family: Fermion
Group: Quark
Interaction: Gravity, Electromagnetic, Weak, Strong
Antiparticle: Antiproton
Discovered: Ernest Rutherford (1919)
Symbol: p+
Mass: 1.
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The nucleus of an atom is the very small dense region of an atom, in its center consisting of nucleons (protons and neutrons). The size (diameter) of the nucleus is in the range of 1.
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atom (Greek ἄτομος or átomos meaning "indivisible") is the smallest particle still characterizing a chemical element.
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chemical element, or element, is a type of atom that is defined by its atomic number; that is, by the number of protons in its nucleus. The term is also used to refer to a pure chemical substance composed of atoms with the same number of protons.
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Flavour in particle physics
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Electron
Theoretical estimates of the electron density for the first few hydrogen atom electron orbitals shown as cross-sections with color-coded probability density
Composition: Elementary particle
Family: Fermion
Group: Lepton
Generation: First
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Theoretical estimates of the electron density for the first few hydrogen atom electron orbitals shown as cross-sections with color-coded probability density
Composition: Elementary particle
Family: Fermion
Group: Lepton
Generation: First
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The mass number (A), also called atomic mass number (not to be confused with atomic number (Z) which denotes the number of protons in a nucleus) or nucleon number, is the number of nucleons (protons and neutrons) in an atomic nucleus.
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Neutron
The quark structure of the neutron.
Composition: one up, two down
Family: Fermion
Group: Quark
Interaction: Gravity, Electromagnetic, Weak, Strong
Antiparticle: Antineutron
Discovered: James Chadwick[1]
Symbol: n
Mass: 1.
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The quark structure of the neutron.
Composition: one up, two down
Family: Fermion
Group: Quark
Interaction: Gravity, Electromagnetic, Weak, Strong
Antiparticle: Antineutron
Discovered: James Chadwick[1]
Symbol: n
Mass: 1.
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Isotopes are any of the several different forms of an element each having different atomic mass (mass number). Isotopes of an element have nuclei with the same number of protons (the same atomic number) but different numbers of neutrons.
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Carbon-14, 14C, or radiocarbon, is a radioactive isotope of carbon discovered on February 27, 1940, by Martin Kamen and Sam Ruben. Its nucleus contains 6 protons and 8 neutrons.
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Radiocarbon dating is a radiometric dating method that uses the naturally occurring isotope carbon-14 (14C) to determine the age of carbonaceous materials up to about 60,000 years.[1] Raw, i.e.
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standard periodic table below.
The periodic table of the chemical elements is a tabular method of displaying the chemical elements. Although precursors to this table exist, its invention is generally credited to Russian chemist Dmitri Mendeleev in 1869.
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Dimitri Ivanovich Mendeleev listen ) (8 February [O.S. 27 January] 1834 in Tobolsk – 2 February [O.S. 20 January] 1907 in Saint Petersburg), was a Russian chemist.
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atomic mass (ma) is the mass of an atom at rest, most often expressed in unified atomic mass units.[1] The atomic mass may be considered to be the total mass of protons, neutrons and electrons in a single atom (when the atom is motionless).
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Iodine (IPA: /ˈaɪədaɪn, ˈaɪədɪn/, or /ˈaɪədiːn/; from Greek: iodes
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4, 6
(mildly acidic oxide)
Electronegativity 2.1 (scale Pauling)
Ionization energies
(more) 1st: 869.3 kJmol−1
2nd: 1790 kJmol−1
3rd: 2698 kJmol−1
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(mildly acidic oxide)
Electronegativity 2.1 (scale Pauling)
Ionization energies
(more) 1st: 869.3 kJmol−1
2nd: 1790 kJmol−1
3rd: 2698 kJmol−1
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Henry Gwyn Jeffreys Moseley (November 23, 1887 – August 10, 1915) was an English physicist. His main contributions to science were the quantitative justification of the previously empirical concept of atomic number, in Moseley's law.
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19th century - 20th century - 21st century
1880s 1890s 1900s - 1910s - 1920s 1930s 1940s
1910 1911 1912 - 1913 - 1914 1915 1916
Year 1913 (MCMXIII
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1880s 1890s 1900s - 1910s - 1920s 1930s 1940s
1910 1911 1912 - 1913 - 1914 1915 1916
Year 1913 (MCMXIII
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X-ray crystallography is the science of determining the arrangement of atoms within a crystal from the manner in which a beam of X-rays is scattered from the electrons within the crystal.
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Flavour in particle physics
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electron configuration is the arrangement of electrons in an atom, molecule, or other physical structure (e.g., a crystal). Like other elementary particles, the electron is subject to the laws of quantum mechanics, and exhibits both particle-like and wave-like nature.
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quantum mechanics is the study of the relationship between energy quanta (radiation) and matter, in particular that between valence shell electrons and photons. Quantum mechanics is a fundamental branch of physics with wide applications in both experimental and theoretical physics.
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An electron shell, also known as a main energy level, is a group of atomic orbitals with the same value of the principal quantum number n. Electron shells are made up of one or more electron subshells, or sublevels
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A chemical bond is the physical process responsible for the attractive interactions between atoms and molecules, and that which confers stability to diatomic and polyatomic chemical compounds.
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- For , see .
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island of stability is a term from nuclear physics that describes the possibility of elements with particularly stable "magic numbers" of protons and neutrons. This would allow certain isotopes of some transuranic elements to be far more stable than others, that is, decay much more
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periodic law which states that certain properties of elements repeat periodically when arranged by atomic number. The table arranges elements into vertical columns (Groups) and horizontal rows (Periods) to display these commonalities.
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