The original table was created without a knowledge of the inner structure of atoms: if one orders the elements by atomic mass, and then plots certain other properties against atomic mass, one sees an undulation or periodicity to these properties as a function of atomic mass. The first to recognize these regularities was the German chemist Johann Wolfgang Döbereiner who, in 1829, noticed a number of triads of similar elements: This was followed by the English chemist John Newlands, who noticed in 1865 that the elements o ...

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Periodic table, Periodic table - Groups, Periodic table - Periodicity of chemical properties, Periodic table - Methods for displaying the periodic table, Periodic table - Standard periodic table, Periodic table - Other depictions, Periodic table - Periodic table structure reflects electron configuration, Periodic table - History, Periodic table - Further resources

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Periodic table, Periodic table - Groups, Periodic table - Periodicity of chemical properties, Periodic table - Methods for displaying the periodic table, Periodic table - Standard periodic table, Periodic table - Other depictions, Periodic table - Periodic table structure reflects electron configuration, Periodic table - History, Periodic table - Further resources

Read more here: » Periodic table: Encyclopedia II - Periodic table - Groups

Periodic table - Standard periodic table. 1Actinides and lanthanides are collectively known as "Rare Earth Metals". 2Alkali metals, alkaline earth metals, transition metals, actinides, lanthanides, and poor metals are all collectively known as "Metals". 3Halogens and noble gases are also non-metals. State at standard temperature and pressure those with atomic number in red are gases those with ...

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Periodic table, Periodic table - Groups, Periodic table - Periodicity of chemical properties, Periodic table - Methods for displaying the periodic table, Periodic table - Standard periodic table, Periodic table - Other depictions, Periodic table - Periodic table structure reflects electron configuration, Periodic table - History, Periodic table - Further resources

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The chalcogens (with the "ch" pronounced with a hard "c" as in "chemistry") are the name for the periodic table group 16 (old-style: VIB or VIA) in the periodic table. It is sometimes known as the oxygen family. It consists of the elements oxygen (O), sulfur (S), selenium (Se), tellurium (Te), the radioactive polonium (Po), and the synthetic ununhexium (Uuh). The compounds of the heavier chalcogens (particularly the sulfides, selenides, and tellurides) are collectively known as chalcogenides. Unless grouped with a heavier cha ...

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A chemical series is a group of chemical elements whose physical and chemical characteristics vary progressively from one end of the series to another. Chemical series were discovered before the creation of the periodic table of the chemical elements, which was created to try to organise the elements according to their chemical properties. Several chemical series correspond exactly to periodic table groups: this is not a coincidence, the physical properties that group them arise from the same atomic orbital configurations that place them in the same group in the periodic table. ...

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The atomic number (Z) is a term used in chemistry and physics to represent the number of protons found in the nucleus of an atom. In an atom of neutral charge, the number of electrons also equals the atomic number. The atomic number originally meant the number of an element's place in the periodic table. When Mendeleyev arranged the known chemical elements grouped by their similarities in chemistry, it was noticeable that placing them in strict order of atomic mass resulted in some mismatches. Iodine and tellurium ...

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43 is the natural number following 42 and preceding 44. << 40 41 42 43 44 45 46 47 48 49 >> List of numbers -- Integers 0 10 20 30 40 50 60 70 80 90 >> 43 number - In mathematics. Forty-three is the 14th smallest prime number. The previous is forty-one, with which it comprises a twin prime, the next is forty-seven. 43 is a centered heptagonal number. 43 is the smallest prime that is not a Chen prime.< ...

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• 43 number - In mathematics
• 43 number - In science
• 43 number - In the periodic table
• 43 number - In astronomy
• 43 number - In other fields

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Chemistry resources is a collection of links and references that are useful for chemistry-related work. This includes free online chemical databases, publications, patents, computer programs, and various tools. Chemistry resources - Free online resources. Chemistry resources - Databases. Chemical catalog Compounds, analytical data Chmoogle The free chemistry search engine PubChem Compound, substance, and bioactivity data NCI Databa ...

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• Chemistry resources - Free online resources
• Chemistry resources - Databases
• Chemistry resources - Online tools
• Chemistry resources - Nomenclature
• Chemistry resources - Periodic tables
• Chemistry resources - Software
• Chemistry resources - Safety

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A less formal description of the electrons in atoms can be found at Electron configuration. In quantum mechanics, the state of an atom, i.e. the eigenstates of the atomic Hamiltonian, are expanded (see configuration interaction expansion and basis (linear algebra)) into linear combinations of anti-symmetrized products (Slater determinants) of one-electron functions. The spatial components of these one-electron functions are called atomic orbitals. (When one considers also their spin c ...

Including:

• Atomic orbital - Hydrogen-like atoms
• Atomic orbital - Qualitative characterization
• Atomic orbital - Limitations on the quantum numbers
• Atomic orbital - The shapes of orbitals
• Atomic orbital - Orbital energy
• Atomic orbital - Electron placement and the periodic table
• Atomic orbital - Related topics

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Table may mean: Table (database) Table (furniture) Table (information), including spreadsheets, etc. Table (jewelery) To table (verb) a proposal Table may also refer to: HTML element#tables Mathematical table Periodic table Truth table Water table See also. Help:Table Wikipedia:How to use tables ...

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Hydrogen (Latin: hydrogenium, from Greek: hydro: water, genes: forming) is a chemical element in the periodic table that has the symbol H and atomic number 1. At standard temperature and pressure it is a colorless, odorless, nonmetallic, univalent, tasteless, highly flammable diatomic gas. Hydrogen is the lightest and most abundant element in the universe. It is present in water, all organic compounds (rare exceptions exist, like buckminsterfullerene) and in all living organisms. Hydrogen is able to react c ...

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• Hydrogen - Basic features
• Hydrogen - Applications
• Hydrogen - History
• Hydrogen - Electron energy levels
• Hydrogen - Occurrence
• Hydrogen - Compounds
• Hydrogen - Forms
• Hydrogen - Isotopes

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The d-block of the periodic table of the elements consists of those periodic table groups that contain elements in which, in the atomic ground state, the highest-energy electron is in a d-orbital. The d-block elements are often also known as transition metals. See also. Periodic table block s-block p-block f-block g-block Electron configuration Periodic tables

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Period and periodic may refer to: Period (music) Period (rhetoric) Historical period Menstrual cycle, relating to the reproductive system full stop, also known as a period, that marks the end of a sentence Science and Mathematics: Orbital period, in astronomy Periodic table, in chemistry Periodic table period, in chemistry Periodic acid, in chemistr ...

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The abundance of a chemical element measures how common the element is, or how much of the element there is. Abundance of the chemical elements - Abundance of elements in the Universe. Hydrogen is the most abundant element in the known Universe; helium is second. However, after this, the rank of abundance does not continue to correspond to the atomic number; oxygen has abundance rank 3, but atomic number 8. All others are orders of magnitude less common. Both helium-3 and helium-4 were produced in th ...

Including:

• Abundance of the chemical elements - Abundance of elements in the Universe
• Abundance of the chemical elements - Abundance of elements in the Solar System
• Abundance of the chemical elements - Abundance of elements in Earth
• Abundance of the chemical elements - Abundance of elements in Earth's crust
• Abundance of the chemical elements - Ocean
• Abundance of the chemical elements - Atmosphere
• Abundance of the chemical elements - Organisms
• Abundance of the chemical elements - Human body

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Dmitri Mendeleev, also spelt Dmitry Mendeleyev, middle name (patronymic) Ivanovich, a Siberian-born Russian chemist, was the first scientist to make a periodic table much like the one we use today. Mendeleev arranged the elements in a table ordered by atomic mass. On March 6, 1869, a formal presentation was made to the Russian Chemical Society, entitled The Dependence Between the Properties of the Atomic Weights of the Elements. His table was published in an obscure Russian journal but quickly republished in a German journal, Zeits ...

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History of the periodic table, History of the periodic table - In the beginning, History of the periodic table - Antoine-Laurent de Lavoisier, History of the periodic table - Alexandre-Emile Béguyer de Chancourtois, History of the periodic table - John Newlands' Octaves, History of the periodic table - The first periodic table, History of the periodic table - Henry Moseley, History of the periodic table - Walter Russell

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Definition and meaning of Periodic Table:

Periodic Table - a chart of the known chemical elements, arranged according to their atomic numbers. Elements with similar physical and chemical properties and similar electron arrangements are in the same column

(Source: US National Oceanic and Atmospheric Administration (NOAA) )

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Elements adjacent to one another within a group have similar physical properties, despite their significant differences in mass. Elements adjacent to one another within a period, or energy level, have similar mass but different properties. For example, very near to nitrogen (N) in the second period of the chart are carbon (C) and oxygen (O). Despite their similarities in mass (only a few atomic mass units), they have extremely different properties, as can be seen by looking at their allotropes: diatomic oxygen is a gas that supports burning, diatomic nitrogen is a gas that d ...

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Periodic table, Periodic table - Groups, Periodic table - Periodicity of chemical properties, Periodic table - Methods for displaying the periodic table, Periodic table - Standard periodic table, Periodic table - Other depictions, Periodic table - Periodic table structure reflects electron configuration, Periodic table - History, Periodic table - Further resources

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The primary determinant of an element's chemical properties is its electron configuration, particularly the valence shell electrons. For instance, all atoms whose four valence electrons are found on the p shell will behave similarly, regardless of which energy level that last p shell is on. The shell in which the atom's outermost electrons reside determines the "block" to which it belongs. Th ...

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Periodic table, Periodic table - Groups, Periodic table - Periodicity of chemical properties, Periodic table - Methods for displaying the periodic table, Periodic table - Standard periodic table, Periodic table - Other depictions, Periodic table - Periodic table structure reflects electron configuration, Periodic table - History, Periodic table - Further resources

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People have known about basic chemical elements such as gold, silver, and copper from antiquity, as these can all be discovered in nature in native form and are relatively simple to mine with primitive tools. Aristotle, a philosopher, theorised that everything is made up of a mixture of one or more of four elements. They were earth, water, air, and fire. This was more like the four states of matter (in the same order): solid, liquid, gas, and plasma, though he also t ...

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History of the periodic table, History of the periodic table - In the beginning, History of the periodic table - Antoine-Laurent de Lavoisier, History of the periodic table - Alexandre-Emile Béguyer de Chancourtois, History of the periodic table - John Newlands' Octaves, History of the periodic table - The first periodic table, History of the periodic table - Henry Moseley, History of the periodic table - Walter Russell

Read more here: » History of the periodic table: Encyclopedia II - History of the periodic table - In the beginning

In 1913, Henry Moseley found a relationship between an element's X-ray wavelength and its atomic number. Before this discovery, atomic numbers were just random numbers based on an element's atomic weight. Moseley's discovery showed that atomic numbers were not arbitrary but had an experimentally measurable basis. Mosley's research also showed that there were gaps in his table at atomic numbers 43 and 61 which are now known to be radioactive and not naturally occurring. Following in the footsteps ...

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History of the periodic table, History of the periodic table - In the beginning, History of the periodic table - Antoine-Laurent de Lavoisier, History of the periodic table - Alexandre-Emile Béguyer de Chancourtois, History of the periodic table - John Newlands' Octaves, History of the periodic table - The first periodic table, History of the periodic table - Henry Moseley, History of the periodic table - Walter Russell

Read more here: » History of the periodic table: Encyclopedia II - History of the periodic table - Henry Moseley