A report on Chemical element and Periodic table

The chemical elements ordered in the periodic table

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

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

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

Idealized order of shell-filling (most accurate for n  ≲ 4.)

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.

Graph of first ionisation energies of the elements in electronvolts (predictions used for elements 105–118)

Flowing liquid mercury. Its liquid state at room temperature is a result of special relativity.

A periodic table colour-coded to show some commonly used sets of similar elements. The categories and their boundaries differ somewhat between sources. Alkali metals
Alkaline earth metals
Lanthanides
Actinides
Transition metals Other metals
Metalloids
Other nonmetals
Halogens
Noble gases

One possible form of the extended periodic table to element 172, suggested by Finnish chemist Pekka Pyykkö. Deviations from the Madelung order (8s < < 6f < 7d < 8p) begin to appear at elements 139 and 140, though for the most part it continues to hold approximately.

Otto Theodor Benfey's spiral periodic table (1964)

Arsenic, an element often called a semi-metal or metalloid

The periodic table, also known as the periodic table of the (chemical) elements, is a tabular display of the chemical elements.

- Periodic table

Much of the modern understanding of elements developed from the work of Dmitri Mendeleev, a Russian chemist who published the first recognizable periodic table in 1869.

- Chemical element

42 related topics with Alpha

Isotope

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In the bottom right corner of J. J. Thomson's photographic plate are the separate impact marks for the two isotopes of neon: neon-20 and neon-22.

Isotopes are two or more types of atoms that have the same atomic number (number of protons in their nuclei) and position in the periodic table (and hence belong to the same chemical element), and that differ in nucleon numbers (mass numbers) due to different numbers of neutrons in their nuclei.

Metal

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Material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, and conducts electricity and heat relatively well.

A metal in the form of a gravy boat made from stainless steel, an alloy largely composed of iron, carbon, and chromium

A metal rod with a hot-worked eyelet. Hot-working exploits the capacity of metal to be plastically deformed.

Samples of babbitt metal, an alloy of tin, antimony, and copper, used in bearings to reduce friction

A sculpture cast in nickel silver—an alloy of copper, nickel, and zinc that looks like silver

Rhodium, a noble metal, shown here as 1 g of powder, a 1 g pressed cylinder, and a 1 g pellet

A sample of diaspore, an aluminum oxide hydroxide mineral, α-AlO(OH)

A neodymium compound alloy magnet of composition Nd2Fe14B on a nickel-iron bracket from a computer hard drive

A pile of compacted steel scraps, ready for recycling

The Artemision Bronze showing either Poseidon or Zeus, c. 460 BCE, National Archaeological Museum, Athens. The figure is more than 2 m in height.

A disc of highly enriched uranium that was recovered from scrap processed at the Y-12 National Security Complex, in Oak Ridge, Tennessee

White-hot steel pours like water from a 35-ton electric furnace, at the Allegheny Ludlum Steel Corporation, in Brackenridge, Pennsylvania.

A Ho-Mg-Zn icosahedral quasicrystal formed as a pentagonal dodecahedron, the dual of the icosahedron

Body-centered cubic crystal structure, with a 2-atom unit cell, as found in e.g. chromium, iron, and tungsten

Face-centered cubic crystal structure, with a 4-atom unit cell, as found in e.g. aluminum, copper, and gold

Hexagonal close-packed crystal structure, with a 6-atom unit cell, as found in e.g. titanium, cobalt, and zinc

Niobium crystals and a 1 cm{{sup|3}} anodized niobium cube for comparison

Molybdenum crystals and a 1 cm{{sup|3}} molybdenum cube for comparison

Tantalum single crystal, some crystalline fragments, and a 1 cm{{sup|3}} tantalum cube for comparison

Tungsten rods with evaporated crystals, partially oxidized with colorful tarnish, and a 1 cm{{sup|3}} tungsten cube for comparison

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

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

Electrum, a natural alloy of silver and gold, was often used for making coins. Shown is the Roman god Apollo, and on the obverse, a Delphi tripod (circa 310–305 BCE).

A plate made of pewter, an alloy of 85–99% tin and (usually) copper. Pewter was first used around the beginning of the Bronze Age in the Near East.

A pectoral (ornamental breastplate) made of tumbaga, an alloy of gold and copper

Arsenic, sealed in a container to prevent tarnishing

Bismuth in crystalline form, with a very thin oxidation layer, and a 1 cm{{sup|3}} bismuth cube

Potassium pearls under paraffin oil. Size of the largest pearl is 0.5 cm.

Aluminum chunk, 2.6 grams, {{nowrap|1=1 x 2 cm}}

Scandium, including a 1 cm{{sup|3}} cube

Lutetium, including a 1 cm{{sup|3}} cube

A metal may be a chemical element such as iron; an alloy such as stainless steel; or a molecular compound such as polymeric sulfur nitride.

Around 95 of the 118 elements in the periodic table are metals (or are likely to be such).

Uranium

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Various militaries use depleted uranium as high-density penetrators.

The most visible civilian use of uranium is as the thermal power source used in nuclear power plants.

Uranium ceramic glaze glowing under UV light Design and developed by Dr. Sencer Sarı

Uranium glass used as lead-in seals in a vacuum capacitor

The planet Uranus, which uranium is named after

Antoine Henri Becquerel discovered the phenomenon of radioactivity by exposing a photographic plate to uranium in 1896.

Cubes and cuboids of uranium produced during the Manhattan project

The mushroom cloud over Hiroshima after the dropping of the uranium-based atomic bomb nicknamed 'Little Boy'

Four light bulbs lit with electricity generated from the first artificial electricity-producing nuclear reactor, EBR-I (1951)

U.S. and USSR/Russian nuclear weapons stockpiles, 1945–2005

Uraninite, also known as pitchblende, is the most common ore mined to extract uranium.

The evolution of Earth's radiogenic heat flow over time: contribution from 235U in red and from 238U in green

Citrobacter species can have concentrations of uranium in their cells 300 times the level of the surrounding environment.

Monthly uranium spot price in US$ per pound. The 2007 price peak is clearly visible.

Uranium in its oxidation states III, IV, V, VI

Uranium hexafluoride is the feedstock used to separate uranium-235 from natural uranium.

Cascades of gas centrifuges are used to enrich uranium ore to concentrate its fissionable isotopes.

World uranium production (mines) and demand<ref name="WNA-WUM" />

alt=A yellow sand-like rhombic mass on black background.|Yellowcake is a concentrated mixture of uranium oxides that is further refined to extract pure uranium.

Uranium is a chemical element with the symbol U and atomic number 92.

It is a silvery-grey metal in the actinide series of the periodic table.

Thorium

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Thorium dioxide has the fluorite crystal structure. Th4+: __ / O2−: __

Crystal structure of thorium tetrafluoride Th4+: __ / F−: __

Sandwich molecule structure of thorocene

$Piano-stool molecule structure of (\h{8}C8H8)ThCl2(THF)2$

Estimated abundances of the 83 primordial elements in the Solar system, plotted on a logarithmic scale. Thorium, at atomic number 90, is one of the rarest elements.

The radiogenic heat from the decay of 232Th (violet) is a major contributor to the earth's internal heat budget. Of the four major nuclides providing this heat, 232Th has grown to provide the most heat as the other ones decayed faster than thorium.

Thor's Fight with the Giants (1872) by Mårten Eskil Winge; Thor, the Norse god of thunder, raising his hammer Mjölnir in a battle against the giants.

Jöns Jacob Berzelius, who first identified thorium as a new element

Glenn T. Seaborg, who settled thorium's location in the f-block

The Indian Point Energy Center (Buchanan, New York, United States), home of the world's first thorium reactor

Yellowed thorium dioxide lens (left), a similar lens partially de-yellowed with ultraviolet radiation (centre), and lens without yellowing (right)

Experiment on the effect of radiation (from an unburned thorium gas mantle) on the germination and growth of timothy-grass seed

Thorium is a weakly radioactive metallic chemical element with the symbol Th and atomic number 90.

In the periodic table, it lies to the right of actinium, to the left of protactinium, and below cerium.

Neptunium

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The 4n + 1 decay chain of neptunium-237, commonly called the "neptunium series"

Dmitri Mendeleev's table of 1871, with an empty space at the position after uranium

Rhenium. For a long time, chemists thought that element 93 would be homologous to rhenium, making the discovery and identification of neptunium nearly impossible.

The 60-inch cyclotron at the Lawrence Radiation Laboratory, University of California, Berkeley, in August 1939

Neptunium was discovered by Edwin McMillan (pictured) and Philip Abelson in 1940.

The planet Neptune, after which neptunium is named

Flowchart, showing the Purex process and the likely oxidation state of neptunium in the process solution.

Neptunium is a chemical element with the symbol Np and atomic number 93.

Its position in the periodic table just after uranium, named after the planet Uranus, led to it being named after Neptune, the next planet beyond Uranus.

Helium

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Sir William Ramsay, the discoverer of terrestrial helium

The cleveite sample from which Ramsay first purified helium

Historical marker, denoting a massive helium find near Dexter, Kansas

The helium atom. Depicted are the nucleus (pink) and the electron cloud distribution (black). The nucleus (upper right) in helium-4 is in reality spherically symmetric and closely resembles the electron cloud, although for more complicated nuclei this is not always the case.

Binding energy per nucleon of common isotopes. The binding energy per particle of helium-4 is significantly larger than all nearby nuclides.

Helium discharge tube shaped like the element's atomic symbol

Liquefied helium. This helium is not only liquid, but has been cooled to the point of superfluidity. The drop of liquid at the bottom of the glass represents helium spontaneously escaping from the container over the side, to empty out of the container. The energy to drive this process is supplied by the potential energy of the falling helium.

Unlike ordinary liquids, helium II will creep along surfaces in order to reach an equal level; after a short while, the levels in the two containers will equalize. The Rollin film also covers the interior of the larger container; if it were not sealed, the helium II would creep out and escape.

Structure of the helium hydride ion, HHe+

Structure of the suspected fluoroheliate anion, OHeF−

The largest single use of liquid helium is to cool the superconducting magnets in modern MRI scanners.

A dual chamber helium leak detection machine

Because of its low density and incombustibility, helium is the gas of choice to fill airships such as the Goodyear blimp.

Helium (from ἥλιος) is a chemical element with the symbol He and atomic number 2.

It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas and the first in the noble gas group in the periodic table.

Atom

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The Geiger–Marsden experiment:
Left: Expected results: alpha particles passing through the plum pudding model of the atom with negligible deflection.
Right: Observed results: a small portion of the particles were deflected by the concentrated positive charge of the nucleus.

The Bohr model of the atom, with an electron making instantaneous "quantum leaps" from one orbit to another with gain or loss of energy. This model of electrons in orbits is obsolete.

The binding energy needed for a nucleon to escape the nucleus, for various isotopes

A potential well, showing, according to classical mechanics, the minimum energy V(x) needed to reach each position x. Classically, a particle with energy E is constrained to a range of positions between x1 and x2.

This diagram shows the half-life (T½) of various isotopes with Z protons and N neutrons.

These electron's energy levels (not to scale) are sufficient for ground states of atoms up to cadmium (5s2 4d10) inclusively. Do not forget that even the top of the diagram is lower than an unbound electron state.

An example of absorption lines in a spectrum

Graphic illustrating the formation of a Bose–Einstein condensate

Scanning tunneling microscope image showing the individual atoms making up this gold (100) surface. The surface atoms deviate from the bulk crystal structure and arrange in columns several atoms wide with pits between them (See surface reconstruction).

Periodic table showing the origin of each element. Elements from carbon up to sulfur may be made in small stars by the alpha process. Elements beyond iron are made in large stars with slow neutron capture (s-process). Elements heavier than iron may be made in neutron star mergers or supernovae after the r-process.

An atom is the smallest unit of ordinary matter that forms a chemical element.

While experimenting with the products of radioactive decay, in 1913 radiochemist Frederick Soddy discovered that there appeared to be more than one type of atom at each position on the periodic table.

Atomic number

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The Rutherford–Bohr model of the hydrogen atom or a hydrogen-like ion (Z > 1). In this model it is an essential feature that the photon energy (or frequency) of the electromagnetic radiation emitted (shown) when an electron jumps from one orbital to another be proportional to the mathematical square of atomic charge (Z2). Experimental measurement by Henry Moseley of this radiation for many elements (from ) showed the results as predicted by Bohr. Both the concept of atomic number and the Bohr model were thereby given scientific credence.

Russian chemist Dmitri Mendeleev, creator of the periodic table.

The atomic number or nuclear charge number (symbol Z) of a chemical element is the charge number of an atomic nucleus.

The conventional symbol Z comes from the German word Zahl 'number', which, before the modern synthesis of ideas from chemistry and physics, merely denoted an element's numerical place in the periodic table, whose order was then approximately, but not completely, consistent with the order of the elements by atomic weights.

Enrico Fermi suggested the existence of transuranium elements in 1934.

Actinide

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Glenn T. Seaborg and his group at the University of California at Berkeley synthesized Pu, Am, Cm, Bk, Cf, Es, Fm, Md, No and element 106, which was later named seaborgium in his honor while he was still living. They also synthesized more than a hundred actinide isotopes.

Actinides have 89−103 protons and usually 117−159 neutrons.

Table of nuclides: Buildup of actinides in a nuclear reactor, including radioative decay

Separation of uranium and plutonium from spent nuclear fuel using the PUREX process

A pellet of 238PuO2 to be used in a radioisotope thermoelectric generator for either the Cassini or Galileo mission. The pellet produces 62 watts of heat and glows because of the heat generated by the radioactive decay (primarily α). Photo is taken after insulating the pellet under a graphite blanket for minutes and removing the blanket.

Einsteinium triiodide glowing in the dark

Interior of a smoke detector containing americium-241.

Self-illumination of a nuclear reactor by Cherenkov radiation.

Schematic illustration of penetration of radiation through sheets of paper, aluminium and lead brick

Uranyl nitrate (UO{{sub|2}}(NO{{sub|3}}){{sub|2}})

Aqueous solutions of uranium III, IV, V, VI salts

Aqueous solutions of neptunium III, IV, V, VI, VII salts

Aqueous solutions of plutonium III, IV, V, VI, VII salts

The actinide or actinoid series encompasses the 15 metallic chemical elements with atomic numbers from 89 to 103, actinium through lawrencium.

In presentations of the periodic table, the f-block elements are customarily shown as two additional rows below the main body of the table.

Plutonium

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A ring of weapons-grade 99.96% pure electrorefined plutonium, enough for one bomb core. The ring weighs 5.3 kg, is ca. 11 cm in diameter and its shape helps with criticality safety.

Uranium-plutonium and thorium-uranium chains

Various oxidation states of plutonium in solution

Plutonium pyrophoricity can cause it to look like a glowing ember under certain conditions.

Twenty micrograms of pure plutonium hydroxide

Sample of plutonium metal displayed at the Questacon museum

Glenn T. Seaborg and his team at Berkeley were the first to produce plutonium.

The dwarf planet Pluto, after which plutonium is named

The Hanford B Reactor face under construction—the first plutonium-production reactor

The Hanford site represents two-thirds of the nation's high-level radioactive waste by volume. Nuclear reactors line the riverbank at the Hanford Site along the Columbia River in January 1960.

Because of the presence of plutonium-240 in reactor-bred plutonium, the implosion design was developed for the "Fat Man" and "Trinity" weapons

The atomic bomb dropped on Nagasaki, Japan in 1945 had a plutonium core.

The 238PuO2 radioisotope thermoelectric generator of the Curiosity rover

A sphere of simulated plutonium surrounded by neutron-reflecting tungsten carbide blocks in a re-enactment of Harry Daghlian's 1945 experiment

Plutonium is a radioactive chemical element with the symbol Pu and atomic number 94.

Alternative names considered by Seaborg and others were "ultimium" or "extremium" because of the erroneous belief that they had found the last possible element on the periodic table.