81 Sentences With "an atom of" | Random Sentence Generator

In effect, methanol is methane (one carbon atom and four hydrogens) plus an atom of oxygen.

In an atom of hydrogen, the north poles of the proton and electron can point in the same or opposite direction.

The RIKEN group first synthesized an atom of element 113 in July of 2004, only 10 months after starting their initial experiments.

The balding and shirtless figure who glares at us in "Tattooed man at a carnival, Md." (21971) requests not an atom of our pity.

The idea was that if they bombarded the bismuth enough times, some bismuth and zinc atoms' nuclei would eventually fuse, creating an atom of element 113.

Absorbing a neutron causes an atom of 235U to split in two (the same process lies at the heart of nuclear power stations and uranium atom bombs).

But every once in a while, a neutrino will hit into an atom of that ice, and breaks it apart, there's a momentary flash of an eerie blue light.

No one has reported an allergic reaction to the film, which is a polymer composed of an atom of oxygen with two atoms of silicon that repeats to form a large molecule.

At Daniel, the sommeliers, with an audience of about 20113, took on five beliefs that may have originated either in custom or with an atom of truth, and over time grew into orthodoxy.

"One hundred billion neutrinos go through your thumbnail every second, but in all likelihood not a single one of them will ever hit an atom of your thumb in your lifetime," said Penn State physicist Doug Cowen, another of the researchers.

" When Alice maintained that she didn't "believe there's an atom of meaning in it," the King was delighted to declare "If there's no meaning in it that saves a world of trouble, you know, as we needn't try to find any.

Although the idea made sense in theory, actually producing an atom of element 113 proved to be a difficult task given the extremely short half-lives of the element 113 isotopes produced by RIKEN, which amount to roughly 1/1000 of a second.

In the early 1940s, scientists determined that one of the elements in the corona was a form of iron that had been stripped of 13 of its electrons, and it takes a massive amount of energy, in the form of heat, to pull electrons away from an atom of iron.

If the situation is not stable or sustainable, what I want to mention is if we did continue farther in— into an atom of the flesh or the metallic fabric of the fork, the micro-weft of the tablecloth, it would be more or less the same kind of utter emptiness— as at the heart of any restaurant there is this dead eye of the sea bass on your plate, its aureole lens, its lightless pupil sunk flush as a thumbtack holding the universe itself in place and I stare at it, and it stares back.

An Atom of time or "a-tom" (“indivisible” in Greek), refers to the smallest possible unit of time.

An atom of thy creation, wildered in the mazes of ignorance and woe, would bow to thy decrees.

The decay energy is the energy released by a radioactive decay. Radioactive decay is the process in which an unstable atomic nucleus loses energy by emitting ionizing particles and radiation. This decay, or loss of energy, results in an atom of one type, called the parent nuclide transforming to an atom of a different type, called the daughter nuclide.

Usually a peroxide or a peracid is used to add an atom of oxygen and convert the -C=C- bond to an epoxide group.

1,2-Difluoroethane is a saturated hydrofluorocarbon containing an atom of fluorine attached to each of two carbons atoms. The formula can be written CH2FCH2F. It is an isomer of 1,1-Difluoroethane. It has a HFC name of HFC-152 with no letter suffix.

The current version, adopted in 1994: :The maximum number of univalent atoms (originally hydrogen or chlorine atoms) that may combine with an atom of the element under consideration, or with a fragment, or for which an atom of this element can be substituted. Hydrogen and chlorine were originally used as examples of univalent atoms, because of their nature to form only one single bond. Hydrogen has only one valence electron and can form only one bond with an atom that has an incomplete outer shell. Chlorine has seven valence electrons and can form only one bond with an atom that donates a valence electron to complete chlorine's outer shell.

The helium is then cooled to separate out the argon, and the argon atoms are counted based on their electron capture radioactive decays. A chlorine detector in the former Homestake Mine near Lead, South Dakota, containing 520 short tons (470 metric tons) of fluid, was the first to detect the solar neutrinos, and made the first measurement of the deficit of electron neutrinos from the sun (see Solar neutrino problem). A similar detector design, with a much lower detection threshold of 0.233 MeV, uses a transformation which is sensitive to lower- energy neutrinos. A neutrino is able to react with an atom of gallium-71, converting it into an atom of the unstable isotope germanium-71.

A schematic nuclear fission chain reaction. 1. A uranium-235 atom absorbs a neutron and fissions into two new atoms (fission fragments), releasing three new neutrons and some binding energy. 2. One of those neutrons is absorbed by an atom of uranium-238 and does not continue the reaction. Another neutron is simply lost and does not collide with anything, also not continuing the reaction. However, the one neutron does collide with an atom of uranium-235, which then fissions and releases two neutrons and some binding energy. 3. Both of those neutrons collide with uranium-235 atoms, each of which fissions and releases between one and three neutrons, which can then continue the reaction.

Iodomethane, also called methyl iodide, and commonly abbreviated "MeI", is the chemical compound with the formula CH3I. It is a dense, colorless, volatile liquid. In terms of chemical structure, it is related to methane by replacement of one hydrogen atom by an atom of iodine. It is naturally emitted by rice plantations in small amounts.

A possible nuclear fission chain reaction. 1. A uranium-235 atom absorbs a neutron, and fissions into two (fission fragments), releasing three new neutrons and a large amount of binding energy. 2. One of those neutrons is absorbed by an atom of uranium-238, and does not continue the reaction. Another neutron leaves the system without being absorbed.

One out of every five rebounds into space, combining to form an atom of hydrogen. Hydrogen shoots off at speeds of around and escapes without being deflected by the Moon's weak gravity. This knowledge provides timely advice for scientists who are readying ESA's BepiColombo mission to Mercury, as that spacecraft will carry two instruments similar to SARA.

This 14 MeV neutron then strikes an atom of uranium-238, causing fission: without this fusion stage, the original 1 MeV neutron hitting an atom of uranium-238 would probably have just been absorbed. This fission then releases energy and also neutrons, which then create more tritium from the remaining lithium-6, and so on, in a continuous cycle. Energy from fission of uranium-238 is useful in weapons: both because depleted uranium is much cheaper than highly enriched uranium and because it cannot go critical and is therefore less likely to be involved in a catastrophic accident. This kind of thermonuclear weapon can produce up to 20% of its yield from fusion, with the rest coming from fission, and is limited in yield to less than one megaton of TNT (4 PJ) equivalent.

Positron decay results in nuclear transmutation, changing an atom of one chemical element into an atom of an element with an atomic number that is less by one unit. Positron emission occurs only very rarely naturally on earth, when induced by a cosmic ray or from one in a hundred thousand decays of potassium-40, a rare isotope, 0.012% of that element on earth. Positron emission should not be confused with electron emission or beta minus decay (β− decay), which occurs when a neutron turns into a proton and the nucleus emits an electron and an antineutrino. Positron emission is different from proton decay, the hypothetical decay of protons, not necessarily those bound with neutrons, not necessarily through the emission of a positron and not as part of nuclear physics, but rather of particle physics.

Metal nitrido complexes are coordination compounds and metal clusters that contain an atom of nitrogen bound only to transition metals. These compounds are molecular, i.e. discrete in contrast to the polymeric, dense nitride materials that are useful in materials science. The distinction between the molecular and solid-state polymers is not always very clear as illustrated by the materials Li6MoN4 and more condensed derivatives such as Na3MoN3.

Depiction of a hydrogen atom showing the diameter as about twice the Bohr model radius. (Image not to scale) A hydrogen atom is an atom of the chemical element hydrogen. The electrically neutral atom contains a single positively charged proton and a single negatively charged electron bound to the nucleus by the Coulomb force. Atomic hydrogen constitutes about 75% of the baryonic mass of the universe.

All consideration of nuclear electrons ended with James Chadwick's discovery of the neutron in 1932. An atom of gold now was seen as containing 118 neutrons rather than 118 nuclear electrons, and its positive charge now was realized to come entirely from a content of 79 protons. After 1932, therefore, an element's atomic number Z was also realized to be identical to the proton number of its nuclei.

Thus, after the binding energy has been removed, binding energy = mass change × c2. This energy is a measure of the forces that hold the nucleons together. It represents energy that must be resupplied from the environment for the nucleus to be broken up into individual nucleons. For example, an atom of deuterium has a mass defect of 0.0023884 amu, and its binding energy is nearly equal to 2.23 MeV.

The structure of chromocene has been verified by X-ray crystallography. The average Cr-C bond length is 215.1(13) pm. Each molecule contains an atom of chromium bound between two planar systems of five carbon atoms known as cyclopentadienyl (Cp) rings in a sandwich arrangement, which is the reason its formula is often abbreviated as Cp2Cr. Chromocene is structurally similar to ferrocene, the prototype for the metallocene class of compounds.

Valence is defined by the IUPAC as:IUPAC Gold Book definition: valence :The maximum number of univalent atoms (originally hydrogen or chlorine atoms) that may combine with an atom of the element under consideration, or with a fragment, or for which an atom of this element can be substituted. An alternative modern description is: : The number of hydrogen atoms that can combine with an element in a binary hydride or twice the number of oxygen atoms combining with an element in its oxide or oxides. This definition differs from the IUPAC definition as an element can be said to have more than one valence. A very similar modern definition given in a recent article defines the valence of a particular atom in a molecule as "the number of electrons that an atom uses in bonding", with two equivalent formulas for calculating valence: :valence = number of electrons in valence shell of free atom – number of non-bonding electrons on atom in molecule, and :valence = number of bonds + formal charge.

The prevailing IUPAC definitions (as taken from the "Gold Book") are: :atomic weight — See: relative atomic massIUPAC Gold Book - atomic weight and :relative atomic mass (atomic weight) — The ratio of the average mass of the atom to the unified atomic mass unit.IUPAC Gold Book - relative atomic mass (atomic weight), A r Here the "unified atomic mass unit" refers to of the mass of an atom of C in its ground state.IUPAC Gold Book - unified atomic mass unit The IUPAC definition of relative atomic mass is: :An atomic weight (relative atomic mass) of an element from a specified source is the ratio of the average mass per atom of the element to 1/12 of the mass of an atom of C. The definition deliberately specifies "An atomic weight…", as an element will have different relative atomic masses depending on the source. For example, boron from Turkey has a lower relative atomic mass than boron from California, because of its different isotopic composition.

The absorption neutron cross section of an isotope of a chemical element is the effective cross sectional area that an atom of that isotope presents to absorption, and is a measure of the probability of neutron capture. It is usually measured in barns (b). Absorption cross section is often highly dependent on neutron energy. As a generality, the likelihood of absorption is proportional to the time the neutron is in the vicinity of the nucleus.

Other compounds can also stimulate cells through OXER1. Many of these compounds differ slightly from 5-oxo-ETE in structure by the replacement of one atom by an atom of a different element, by the loss of one or more atoms, and/or by the presence of a functional group not found in 5-oxo-ETE. These compounds are termed 5-oxo-ETE analogs or members of the 5-oxo-ETE family of agonists.

We used to meet in days of considerable excitement, and address the people on our respective sides; but there never was an atom of ill will between us." Within ten weeks of the election, the two were exchanging friendly letters, and Monroe purchased for Madison four tickets in the Fredericksburg Academy lottery, one of which won. According to Stewart, "Barely thirty years old, Monroe had time to make his way. Losing to the prominent Madison was no disgrace.

The first real experiment to follow Wheeler's intention for a double-slit apparatus to be subjected to end-game determination of detection method is the one by Walborn et al. Researchers with access to radio telescopes originally designed for SETI research have explicated the practical difficulties of conducting the interstellar Wheeler experiment.Quantum Astronomy (IV): Cosmic-Scale Double- Slit Experiment A recent experiment by Manning et al. confirms the standard predictions of standard quantum mechanics with an atom of Helium.

Two materials may form a compound at the joint. The strongest joints are where atoms of the two materials share or swap electrons (known respectively as covalent bonding or ionic bonding). A weaker bond is formed if a hydrogen atom in one molecule is attracted to an atom of nitrogen, oxygen, or fluorine in another molecule, a phenomenon called hydrogen bonding. Chemical adhesion occurs when the surface atoms of two separate surfaces form ionic, covalent, or hydrogen bonds.

Potassium ferrooxalate, also known as potassium bisoxalatoferrate(II), is a salt with the formula [], sometimes abbreviated . The ferrooxalate anion (negative ion) is a transition metal complex, consisting of an atom of iron in the +2 oxidation state bound to two bidentate oxalate ions . The anion charge is balanced by two cations (positive ions) of potassium .J. Ladriere (1992): "Mössbauer study on the thermal decomposition of potassium tris (oxalato) ferrate(III) trihydrate and bis (oxalato) ferrate(II) dihydrate".

Rhodocene, formally known as bis(η5-cyclopentadienyl)rhodium(II), is a chemical compound with the formula [Rh(C5H5)2]. Each molecule contains an atom of rhodium bound between two planar aromatic systems of five carbon atoms known as cyclopentadienyl rings in a sandwich arrangement. It is an organometallic compound as it has (haptic) covalent rhodium–carbon bonds. The [Rh(C5H5)2] radical is found above 150 °C or when trapped by cooling to liquid nitrogen temperatures (−196 °C).

Leptoquarks, predicted to be nearly as heavy as an atom of lead, could only be created at high energies, and would decay rapidly. A so-called third generation leptoquark, for example, might decay into a bottom quark and a tau lepton. Some theorists proposed that data recorded in experiments at the HERA accelerator at DESY could hint at leptoquarks, which would be a new force that bonds positrons and quarks. Also preons at high energies were considered.

The discovery of isotopes of oxygen in 1929 required a more precise definition of the unit. Unfortunately, two distinct definitions came into use. Chemists choose to define the AMU as 1/16 of the average mass of an oxygen atom as found in nature; that is, the average of the masses of the known isotopes, weighted by their natural abundance. Physicists, on the other hand, defined it as 1/16 of the mass of an atom of the isotope oxygen-16 (16O).

By year's end, the first chapter incorporated in Oklahoma with Anderson as its president. It had 85 members and a chapter name, Atomaton (for "an atom of an idea and a ton of energy") that recognized the Atomic Age. Sweet Adelines went international on March 23, 1953 when the first chapter outside the U.S. was chartered in Brandon, Manitoba, Canada. Even though there were international chapters, it was not until May 1991 that the name officially changed to Sweet Adelines International.

This means that 2.23 MeV of energy are required to disintegrate an atom of deuterium. The energy given off during either nuclear fusion or nuclear fission is the difference of the binding energies of the "fuel," i.e. the initial nuclide(s), from that of the fission or fusion products. In practice, this energy may also be calculated from the substantial mass differences between the fuel and products, which uses previous measurements of the atomic masses of known nuclides, which always have the same mass for each species.

A helium atom is an atom of the chemical element helium. Helium is composed of two electrons bound by the electromagnetic force to a nucleus containing two protons along with either one or two neutrons, depending on the isotope, held together by the strong force. Unlike for hydrogen, a closed-form solution to the Schrödinger equation for the helium atom has not been found. However, various approximations, such as the Hartree–Fock method, can be used to estimate the ground state energy and wavefunction of the atom.

William Thomson, later to become Lord Kelvin, became concerned with the nature of Dalton's chemical elements, whose atoms appeared in only a few forms but in vast numbers. He was inspired by Helmholz' findings, reasoning that the aether, a substance then hypothesised to pervade all of space, should be capable of supporting such stable vortices. According to Helmholtz’ theorems, these vortices would correspond to different kinds of knot. Thomson suggested that each type of knot might represent an atom of a different chemical element.

He mentioned it only in passing, as of minimal use when it came to explaining observed stratigraphy. Brown found it particularly sinister that Buckland denied that the Flood must have been universal. Pye Smith's view was > The best friends of Science will unite with [Brown] in deprecating the pride > and vanity which pretend to carry researches beyond the limits which the > Author of our nature has prescribed. But he has not brought an atom of > evidence to prove that the efforts of Geology [...] involve any excursion > whatsoever out of those limits.

Pentaborane was evaluated by both the U.S. and Russian armed services as a so-called "exotic fuel". Because simple boron compounds burn with a characteristic green flame, the nickname for this fuel in the U.S. industry was "Green Dragon". In terms of heat of combustion, pentaborane surpasses its equivalent carbon compounds because their self-linking element, carbon, weighs more than one atomic mass unit more than an atom of boron, and some boranes contain more hydrogen than the carbon equivalent. The ease of breaking the chemical bonds of the compound is also taken into consideration.

AMANDA was used to generate neutrino maps of the northern sky to search for extraterrestrial neutrino sources and to search for dark matter. AMANDA has been upgraded to the IceCube observatory, eventually increasing the volume of the detector array to one cubic kilometer. Ice Cube sits deep underneath the South Pole in a cubic kilometre of perfectly clear, bubble-free ancient ice. Like AMANDA it relies on detecting the flickers of light emitted on the exceedingly rare occasions when a neutrino does interact with an atom of ice or water.

Neutron emission is a mode of radioactive decay in which one or more neutrons are ejected from a nucleus. It occurs in the most neutron-rich/proton- deficient nucleides, and also from excited states of other nucleides as in photoneutron emission and beta-delayed neutron emission. As only a neutron is lost by this process the number of protons remains unchanged, and an atom does not become an atom of a different element, but a different isotope of the same element. Neutrons are also produced in the spontaneous and induced fission of certain heavy nucleides.

The simplest atomic orbitals are those that are calculated for systems with a single electron, such as the hydrogen atom. An atom of any other element ionized down to a single electron is very similar to hydrogen, and the orbitals take the same form. In the Schrödinger equation for this system of one negative and one positive particle, the atomic orbitals are the eigenstates of the Hamiltonian operator for the energy. They can be obtained analytically, meaning that the resulting orbitals are products of a polynomial series, and exponential and trigonometric functions.

Lithium atom A lithium atom is an atom of the chemical element lithium. Lithium is composed of three electrons bound by the electromagnetic force to a nucleus containing three protons along with either three or four neutrons, depending on the isotope, held together by the strong force. Similarly to the case of the helium atom, a closed-form solution to the Schrödinger equation for the lithium atom has not been found. However, various approximations, such as the Hartree–Fock method, can be used to estimate the ground state energy and wavefunction of the atom.

Research in the field flourished after this breakthrough, and to date more than 25 nuclides have been found to exhibit proton emission. The study of proton emission has aided the understanding of nuclear deformation, masses and structure, and it is an example of quantum tunneling. Two examples of nuclides that emit neutrons are beryllium-13 (mean life ) and helium-5 (). Since only a neutron is lost in this process, the atom does not gain or lose any protons, and so it does not become an atom of a different element.

A chemical species with a lower electronegativity than oxygen can serve as a reducing equivalent when it covalently binds to an oxygen atom. Oxygen is highly electronegative and will have a greater affinity for electrons in a covalent bond, resulting in the reduction of the oxygen atom. When an atom of lower electronegativity forms a bond with oxygen it is oxidized because the electrons are pulled closer to oxygen and away from that atom. For instance, consider the formation of a carboxylic acid from the oxidation of an aldehyde.

For elements that combined in multiple ratios, such as the then-known two oxides of carbon or the three oxides of nitrogen, their combinations were assumed to be the simplest ones possible. For example, if two such combinations are known, one must consist of an atom of each element, and the other must consist of one atom of one element and two atoms of the other. This was merely an assumption, derived from faith in the simplicity of nature. No evidence was then available to scientists to deduce how many atoms of each element combine to form molecules.

Ernst Otto Fischer in 1962 discovered tetracyclopentadienyluranium Cp4U by reaction of KCp with UCl4 (6% yield) as a compound stable in air as a solid but not in solution. A zero molecular dipole moment and IR spectroscopy revealed that it was also a sandwich compound with uranium in a tetrahedral molecular geometry. In 1970, Fischer added Cp3U to the list of known organouranium compounds by reduction of Cp4U with elemental uranium. In 1968, the group of Andrew Streitwieser prepared the stable but pyrophoric compound uranocene (COT)2U, which has an atom of uranium sandwiched between two cyclooctatetraenide anions (D8h molecular symmetry).

The generation of discrete Townsend avalanches in a proportional counter. Plot of electric field strength at the anode, showing the boundary of avalanche region. In a proportional counter the fill gas of the chamber is an inert gas which is ionized by incident radiation, and a quench gas to ensure each pulse discharge terminates; a common mixture is 90% argon, 10% methane, known as P-10. An ionizing particle entering the gas collides with an atom of the inert gas and ionizes it to produce an electron and a positively charged ion, commonly known as an "ion pair".

The CsCl (B2) Structure One structure is the "interpenetrating primitive cubic" structure, also called the "caesium chloride" structure. Each of the two atom types forms a separate primitive cubic lattice, with an atom of one type at the center of each cube of the other type. In the unit cell of CsCl, each ion is at the center of a cube of ions of the opposite kind, so the co - ordination number is eight. Altogether, the arrangement of atoms is the same as body-centered cubic, but with alternating types of atoms at the different lattice sites (see picture here).

Ionic bonding can result from a redox reaction when atoms of an element (usually metal), whose ionization energy is low, give some of their electrons to achieve a stable electron configuration. In doing so, cations are formed. An atom of another element (usually nonmetal) with greater electron affinity accepts the electron(s) to attain a stable electron configuration, and after accepting electron(s) an atom becomes an anion. Typically, the stable electron configuration is one of the noble gases for elements in the s-block and the p-block, and particular stable electron configurations for d-block and f-block elements.

However, while this equality can be assumed for almost all practical purposes, it is now only approximate, because of the way mole was redefined on 20 May 2019. In general, the mass in daltons of an atom is numerically close, but not exactly equal to the number of nucleons A contained in its nucleus. It follows that the molar mass of a compound (grams per mole) is numerically close to the average number of nucleons contained in each molecule. By definition, the mass of an atom of carbon-12 is 12 daltons, which corresponds with the number of nucleons that it has (6 protons and 6 neutrons).

Bender and Flexo hit it off, but Flexo soon begins to grate on the nerves of Fry, who suspects him of being evil, despite his behavior being similar to Bender's. The Professor reveals an atom of the fictional element Jumbonium, which the crew is to deliver to the Miss Universe pageant, to be held on Tova 9. Due to the value of the atom, the Professor hires Flexo as additional security. Leela assigns Fry, Bender, and Flexo shifts guarding the atom, but when Fry's shift comes up he falls asleep due to staying up during all of Flexo's shift, and the atom is stolen.

Optical ionization schemes are developed to produce element-selective ion source for various elements. Most of the elements of the periodic table have been resonantly ionized by using one of five major optical routes based on the principle of RIMS. The routes were formed by the absorption of two or three photons to achieve excitation and ionization and are provided on the basis of optically possible transitions between atomic levels in a process called the bound-bound transition. For an atom of the element to be promoted to a bound- continuum, the energies emitted from the photons must be within the energy range of the selected tunable lasers.

Since then, this had become - and remains - a staple of the alternate history genre. A number of alternate history stories and novels appeared in the late 19th and early 20th centuries (see, for example, Charles Petrie's If: A Jacobite Fantasy [1926]). In 1931, British historian Sir John Squire collected a series of essays from some of the leading historians of the period for his anthology If It Had Happened Otherwise. In this work, scholars from major universities (as well as important non-academic authors) turned their attention to such questions as "If the Moors in Spain Had Won" and "If Louis XVI Had Had an Atom of Firmness".

DMT has been used in South America since pre-Columbian times. DMT was first synthesized in 1931 by chemist Richard Helmuth Fredrick Manske (born 1901 in Berlin, Germany – 1977). In general, its discovery as a natural product is credited to Brazilian chemist and microbiologist Oswaldo Gonçalves de Lima (1908–1989) who, in 1946, isolated an alkaloid he named nigerina (nigerine) from the root bark of jurema preta, that is, Mimosa tenuiflora. However, in a careful review of the case Jonathan Ott shows that the empirical formula for nigerine determined by Gonçalves de Lima, which notably contains an atom of oxygen, can match only a partial, "impure" or "contaminated" form of DMT.

Heavy-water reactors may pose a greater risk of nuclear proliferation versus comparable light-water reactors due to the low neutron absorption properties of heavy water, discovered in 1937 by Hans von Halban and Otto Frisch. Occasionally, when an atom of 238U is exposed to neutron radiation, its nucleus will capture a neutron, changing it to 239U. The 239U then rapidly undergoes two β− decays — both emitting an electron and an antineutrino, the first one transmuting the 239U into 239Np, and the second one transmuting the 239Np into 239Pu. Although this process takes place with other moderators such as ultra-pure graphite or beryllium, heavy water is by far the best.

Each atomic number identifies a specific element, but not the isotope; an atom of a given element may have a wide range in its number of neutrons. The number of nucleons (both protons and neutrons) in the nucleus is the atom's mass number, and each isotope of a given element has a different mass number. For example, carbon-12, carbon-13, and carbon-14 are three isotopes of the element carbon with mass numbers 12, 13, and 14, respectively. The atomic number of carbon is 6, which means that every carbon atom has 6 protons, so that the neutron numbers of these isotopes are 6, 7, and 8 respectively.

A redox reaction is the force behind an electrochemical cell like the Galvanic cell pictured. The battery is made out of a zinc electrode in a ZnSO4 solution connected with a wire and a porous disk to a copper electrode in a CuSO4 solution. In this type of reaction, a metal atom in a compound (or in a solution) is replaced by an atom of another metal. For example, copper is deposited when zinc metal is placed in a copper(II) sulfate solution: Zn(s)+ CuSO4(aq) → ZnSO4(aq) + Cu(s) In the above reaction, zinc metal displaces the copper(II) ion from copper sulfate solution and thus liberates free copper metal.

Various atoms and molecules as depicted in John Dalton's A New System of Chemical Philosophy (1808). Dalton published his first table of relative atomic weights containing six elements (hydrogen, oxygen, nitrogen, carbon, sulfur and phosphorus), relative to the weight of an atom of hydrogen conventionally taken as 1. Since these were only relative weights, they do not have a unit of weight attached to them. Dalton provided no indication in this paper how he had arrived at these numbers, but in his laboratory notebook, dated 6 September 1803, is a list in which he set out the relative weights of the atoms of a number of elements, derived from analysis of water, ammonia, carbon dioxide, etc.

An absorption edge, absorption discontinuity or absorption limit is a sharp discontinuity in the absorption spectrum of a substance. These discontinuities occur at wavelengths where the energy of an absorbed photon corresponds to an electronic transition or ionization potential. When the quantum energy of the incident radiation becomes smaller than the work required to eject an electron from one or other quantum states in the constituent absorbing atom, the incident radiation ceases to be absorbed by that state. For example, incident radiation on an atom of a wavelength that has a corresponding energy just below the binding energy of the K-shell electron in that atom cannot eject the K-shell electron.

There are numerous experiments worldwide attempting to detect the energy deposition that is expected to occur when a WIMP directly collides with an atom of ordinary matter. Ultra sensitive experiments are required to detect the low energy and extremely rare interaction that is predicted to occur between a WIMP and the nucleus of an atom in a target material. The DRIFT detectors vary from the majority of WIMP detectors in their use of a low pressure gas as a target material. The low pressure gas means that an interaction within the detector causes an ionisation track of measurable length compared to the point like interactions seen in detectors with solid or liquid target materials.

Evolution of spatial resolution achieved with optical, transmission (TEM) and aberration-corrected electron microscopes (ACTEM). Transmission Electron Aberration-Corrected Microscope (TEAM) is a collaborative research project between four US laboratories and two companies. The project's main activity is design and application of a transmission electron microscope (TEM) with a spatial resolution below 0.05 nanometers, which is roughly half the size of an atom of hydrogen. The project is based at the Lawrence Berkeley National Laboratory in Berkeley, California and involves Argonne National Laboratory, Oak Ridge National Laboratory and Frederick Seitz Materials Research Laboratory at the University of Illinois at Urbana-Champaign, as well as FEI and CEOS companies, and is supported by the U.S. Department of Energy.

The dalton or unified atomic mass unit (symbols: Da or u) is a unit of mass widely used in physics and chemistry. It is defined as 1/12 of the mass of an unbound neutral atom of carbon-12 in its nuclear and electronic ground state and at rest. The atomic mass constant, denoted mu is defined identically, giving . This unit is commonly used in physics and chemistry to express the mass of atomic-scale objects, such as atoms, molecules, and elementary particles, both for discrete instances and multiple types of ensemble averages. For example, an atom of helium-4 has a mass of . This is an intrinsic property of the isotope and all helium-4 have the same mass.

In the basic method, a molecule is prepared where the vacant bond of the desired radical or ion is satisfied by an atom of tritium , the radioactive isotope of hydrogen with mass number 3. As the tritium undergoes beta decay (with a half-life of 12.32 years), it is transformed into an ion of helium-3, creating the cation . In the decay, an electron and an antineutrino are ejected at great speed from the tritium nucleus, changing one of the neutrons into a proton with the release of 18,600 electronvolts (eV) of energy. The neutrino escapes the system; the electron is generally captured within a short distance, but far enough away from the site of the decay that it can be considered lost from the molecule.

After graduating from Magdalene College in 1921, Blackett spent ten years working at the Cavendish Laboratory as an experimental physicist with Ernest Rutherford and in 1923 became a fellow of King's College, Cambridge, a position he held until 1933. Rutherford had found out that the nucleus of the nitrogen atom could be disintegrated by firing fast alpha particles into nitrogen. He asked Blackett to use a cloud chamber to find visible tracks of this disintegration, and by 1925, he had taken 23,000 photographs showing 415,000 tracks of ionized particles. Eight of these were forked, and this showed that the nitrogen atom-alpha particle combination had formed an atom of fluorine, which then disintegrated into an isotope of oxygen and a proton.

The time it takes for a single parent atom to decay to an atom of its daughter isotope can vary widely, not only between different parent-daughter pairs, but also randomly between identical pairings of parent and daughter isotopes. The decay of each single atom occurs spontaneously, and the decay of an initial population of identical atoms over time t, follows a decaying exponential distribution, e−λt, where λ is called a decay constant. One of the properties of an isotope is its half-life, the time by which half of an initial number of identical parent radioisotopes have decayed to their daughters, which is inversely related to λ. Half-lives have been determined in laboratories for many radioisotopes (or radionuclides).

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. An isotopic tracer, (also "isotopic marker" or "isotopic label"), is used in chemistry and biochemistry to help understand chemical reactions and interactions. In this technique, one or more of the atoms of the molecule of interest is substituted for an atom of the same chemical element, but of a different isotope (like a radioactive isotope used in radioactive tracing). Because the labeled atom has the same number of protons, it will behave in almost exactly the same way as its unlabeled counterpart and, with few exceptions, will not interfere with the reaction under investigation.

In phase I, a variety of enzymes act to introduce reactive and polar groups into their substrates. One of the most common modifications is hydroxylation catalysed by the cytochrome P-450-dependent mixed-function oxidase system. These enzyme complexes act to incorporate an atom of oxygen into nonactivated hydrocarbons, which can result in either the introduction of hydroxyl groups or N-, O- and S-dealkylation of substrates. The reaction mechanism of the P-450 oxidases proceeds through the reduction of cytochrome- bound oxygen and the generation of a highly-reactive oxyferryl species, according to the following scheme: :O2 \+ NADPH + H+ \+ RH → NADP+ \+ H2O + ROH Phase I reactions (also termed nonsynthetic reactions) may occur by oxidation, reduction, hydrolysis, cyclization, decyclization, and addition of oxygen or removal of hydrogen, carried out by mixed function oxidases, often in the liver.

The direction of the magnetic moment of any elementary particle is entirely determined by the direction of its spin, with the negative value indicating that any electron's magnetic moment is antiparallel to its spin. The net magnetic moment of any system is a vector sum of contributions from one or both types of sources. For example, the magnetic moment of an atom of hydrogen-1 (the lightest hydrogen isotope, consisting of a proton and an electron) is a vector sum of the following contributions: # the intrinsic moment of the electron, # the orbital motion of the electron around the proton, # the intrinsic moment of the proton. Similarly, the magnetic moment of a bar magnet is the sum of the contributing magnetic moments, which include the intrinsic and orbital magnetic moments of the unpaired electrons of the magnet's material and the nuclear magnetic moments.

Mel Brooks played a comic version of Louis XVI in The History of the World Part 1, portraying him as a libertine who has such distaste for the peasantry he uses them as targets in skeet shooting. In the 1996 film Ridicule; Urbain Cancelier plays Louis. Louis XVI has been the subject of novels as well, including two of the alternate histories anthologized in If It Had Happened Otherwise (1931): "If Drouet's Cart Had Stuck" by Hilaire Belloc and "If Louis XVI Had Had an Atom of Firmness" by André Maurois, which tell very different stories but both imagine Louis surviving and still reigning in the early 19th century. Louis appears in the children's book Ben and Me by Robert Lawson but does not appear in the 1953 animated short film based on the same book.

In blood, the heme group of hemoglobin binds oxygen when it is present, changing hemoglobin's color from bluish red to bright red.CO2 is released from another part of the hemoglobin molecule, as its acid, which causes CO2 to be released from bicarbonate, its major reservoir in blood plasma (see Bohr effect) Vertebrate animals use hemoglobin in their blood to transport oxygen from their lungs to their tissues, but other animals use hemocyanin (molluscs and some arthropods) or hemerythrin (spiders and lobsters).Figures given are for values up to 50 miles above the surface A liter of blood can dissolve 200 cc of oxygen gas, which is much more than water can dissolve. After being carried in blood to a body tissue in need of oxygen, O2 is handed-off from the heme group to monooxygenase, an enzyme that also has an active site with an atom of iron.