A report on Chemical element

The chemical elements ordered in the periodic table

$Estimated distribution of dark matter and dark energy in the universe. Only the fraction of the mass and energy in the universe labeled "atoms" is composed of chemical elements.$

Periodic table showing the cosmogenic origin of each element in the Big Bang, or in large or small stars. Small stars can produce certain elements up to sulfur, by the alpha process. Supernovae are needed to produce "heavy" elements (those beyond iron and nickel) rapidly by neutron buildup, in the r-process. Certain large stars slowly produce other elements heavier than iron, in the s-process; these may then be blown into space in the off-gassing of planetary nebulae

Abundances of the chemical elements in the Solar System. Hydrogen and helium are most common, from the Big Bang. The next three elements (Li, Be, B) are rare because they are poorly synthesized in the Big Bang and also in stars. The two general trends in the remaining stellar-produced elements are: (1) an alternation of abundance in elements as they have even or odd atomic numbers (the Oddo-Harkins rule), and (2) a general decrease in abundance as elements become heavier. Iron is especially common because it represents the minimum energy nuclide that can be made by fusion of helium in supernovae.

Mendeleev's 1869 periodic table: An experiment on a system of elements. Based on their atomic weights and chemical similarities.

Species of atoms that have a given number of protons in their nuclei, including the pure substance consisting only of that species.

- Chemical element

148 related topics with Alpha

Transition metal

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In chemistry, the term transition metal (or transition element) has three possible definitions:

From left to right, aqueous solutions of: (red); (orange); (yellow); (turquoise); (blue); (purple).

Oxidation states of the transition metals. The solid dots show common oxidation states, and the hollow dots show possible but unlikely states.

The IUPAC definition defines a transition metal as "an element whose atom has a partially filled d sub-shell, or which can give rise to cations with an incomplete d sub-shell".

Crystals of osmium, a heavy metal nearly twice as dense as lead

Heavy metals

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Heavy metals are generally defined as metals with relatively high densities, atomic weights, or atomic numbers.

In a cello (example shown above) or a viola the C-string sometimes incorporates tungsten; its high density permits a smaller diameter string and improves responsiveness.

The Statue of Liberty. A stainless steel alloy armature provides structural strength; a copper skin confers corrosion resistance.

Cerium(IV) oxide (sample shown above) is used as a catalyst in self-cleaning ovens.

Neodymium sulfate (Nd2(SO4)3), used to colour glassware

The Topaz Solar Farm, in southern California, features nine million cadmium-tellurium photovoltaic modules covering an area of 25.6 km2.

An X-ray tube with a rotating anode, typically a tungsten-rhenium alloy on a molybdenum core, backed with graphite

alt=A silvery finger of chromium irregularly encrusted with diamond-like chunks of chromium of varying size. There is also a one-third sized version of the finger and three roughly hewn gem-like chunks of chromium, as well as the cube. There is a partial reflection of one of the three gem-like chunks in one of the faces of the cube.| Chromium crystals and 1 cm{{sup|3}} cube

alt=Two dull silver clusters of crystalline shards| Arsenic, sealed in a container to stop tarnishing

alt=A more or less smooth silvery finger of cadmium with some slightly angled faces plus a dull cube| Cadmium bar and 1 cm{{sup|3}} cube

alt=A silvery molasses- like liquid being poured into a circular container with a height equivalent to a smaller coin on its edge| Mercury being poured into a petri dish

alt=Three, dark broccoli shaped clumps of oxidised lead with grossly distended buds, and a cube of lead which has a dull silvery appearance.| Oxidised lead nodules and 1 cm{{sup|3}} cube

The definitions surveyed in this article encompass up to 96 out of the 118 known chemical elements; only mercury, lead and bismuth meet all of them.

Iron

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Magnetization curves of 9 ferromagnetic materials, showing saturation. 1.Sheet steel, 2.Silicon steel, 3.Cast steel, 4.Tungsten steel, 5.Magnet steel, 6.Cast iron, 7.Nickel, 8.Cobalt, 9.Magnetite

A polished and chemically etched piece of an iron meteorite, believed to be similar in composition to the Earth's metallic core, showing individual crystals of the iron-nickel alloy (Widmanstatten pattern)

Banded iron formation in McKinley Park, Minnesota.

Hydrated iron(III) chloride (ferric chloride)

Comparison of colors of solutions of ferrate (left) and permanganate (right)

Blue-green iron(II) sulfate heptahydrate

The two enantiomorphs of the ferrioxalate ion

Crystal structure of iron(II) oxalate dihydrate, showing iron (gray), oxygen (red), carbon (black), and hydrogen (white) atoms.

Blood-red positive thiocyanate test for iron(III)

Iron harpoon head from Greenland. The iron edge covers a narwhal tusk harpoon using meteorite iron from the Cape York meteorite, one of the largest iron meteorites known.

The symbol for Mars has been used since antiquity to represent iron.

The iron pillar of Delhi is an example of the iron extraction and processing methodologies of early India.

Coalbrookdale by Night, 1801. Blast furnaces light the iron making town of Coalbrookdale.

"Gold gab ich für Eisen" – "I gave gold for iron". German-American brooch from WWI.

17th century Chinese illustration of workers at a blast furnace, making wrought iron from pig iron

How iron was extracted in the 19th century

This heap of iron ore pellets will be used in steel production.

A pot of molten iron being used to make steel

Photon mass attenuation coefficient for iron.

Structure of Heme b; in the protein additional ligand(s) would be attached to Fe.

A heme unit of human carboxyhemoglobin, showing the carbonyl ligand at the apical position, trans to the histidine residue

Iron is a chemical element with symbol Fe (from ferrum) and atomic number 26.

Lanthanide

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A solution of 4% holmium oxide in 10% perchloric acid, permanently fused into a quartz cuvette as a wavelength calibration standard

The lanthanide or lanthanoid series of chemical elements comprises the 15 metallic chemical elements with atomic numbers 57–71, from lanthanum through lutetium.

Promethium

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Promethium(III) chloride being used as a light source for signals in a heat button

Promethium is a chemical element with the symbol Pm and atomic number 61.

Steam and liquid water are two different forms of the same chemical (pure) substance: water.

Chemical substance

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Form of matter having constant chemical composition and characteristic properties.

Colors of a single chemical (Nile red) in different solvents, under visible and UV light, showing how the chemical interacts dynamically with its solvent environment.

Native sulfur crystals. Sulfur occurs naturally as elemental sulfur, in sulfide and sulfate minerals and in hydrogen sulfide.

Potassium ferricyanide is a compound of potassium, iron, carbon and nitrogen; although it contains cyanide anions, it does not release them and is nontoxic.

Cranberry glass, while appearing homogeneous, is a mixture consisting of glass and gold colloidal particles of about 40nm in diameter, giving it a red color.

Chemicals in graduated cylinders and beaker.

Some references add that chemical substance cannot be separated into its constituent elements by physical separation methods, i.e., without breaking chemical bonds.

Atomic orbital

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Domain coloring of a

3D views of some hydrogen-like atomic orbitals showing probability density and phase (g orbitals and higher are not shown)

The Rutherford–Bohr model of the hydrogen atom.

Energetic levels and sublevels of polyelectronic atoms.

Experimentally imaged 1s and 2p core-electron orbitals of Sr, including the effects of atomic thermal vibrations and excitation broadening, retrieved from energy dispersive x-ray spectroscopy (EDX) in scanning transmission electron microscopy (STEM).

The 1s, 2s, and 2p orbitals of a sodium atom.

Atomic orbitals spdf m-eigenstates and superpositions

Electron atomic and molecular orbitals. The chart of orbitals (left) is arranged by increasing energy (see Madelung rule). Note that atomic orbits are functions of three variables (two angles, and the distance r from the nucleus). These images are faithful to the angular component of the orbital, but not entirely representative of the orbital as a whole.

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$Wave function of 1s orbital (real part, 2D-cut, <math>r_{max}=2 a_0</math>)$

$Wave function of 2s orbital (real part, 2D-cut, <math>r_{max}=10 a_0</math>)$

$Wave function of 3s orbital (real part, 2D-cut, <math>r_{max}=20 a_0</math>)$

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$Wave function of 2p orbital (real part, 2D-cut, <math>r_{max}=10 a_0</math>)$

$Wave function of 3p orbital (real part, 2D-cut, <math>r_{max}=20 a_0</math>)$

$Wave function of 4p orbital (real part, 2D-cut, <math>r_{max}=25 a_0</math>)$

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The repeating periodicity of blocks of 2, 6, 10, and 14 elements within sections of the periodic table arises naturally from the total number of electrons that occupy a complete set of s, p, d, and f orbitals, respectively, though for higher values of quantum number n, particularly when the atom bears a positive charge, the energies of certain sub-shells become very similar and so the order in which they are said to be populated by electrons (e.g., Cr = [Ar]4s13d5 and Cr2+ = [Ar]3d4) can only be rationalized somewhat arbitrarily.

Boiling or sublimation temperature dependence for halogens at various pressures. The vertical bar indicates the melting point

These 34 primordial radionuclides represent isotopes of 28 separate elements.