112 Sentences With "monatomic" | Random Sentence Generator

It is a colorless, odorless, tasteless, non-toxic, inert and monatomic gas.

An "improvement" of the monatomic swords invented by the protagonist. Made of a disc of thin steel, with monatomic blades glued to all sides (from broken monatomic swords). This disc can be thrown at an enemy; however, a professional fighter can dodge such a throw. Several different versions of the weapon have been invented.

In physics and chemistry, "monatomic" is a combination of the words "mono" and "atomic", and means "single atom". It is usually applied to gases: a monatomic gas is one in which atoms are not bound to each other. Examples at standard conditions include the noble gases argon, krypton, and xenon, though all chemical elements will be monatomic in the gas phase at sufficiently high temperatures. The thermodynamic behavior of a monatomic gas is extremely simple when compared to polyatomic gases because it is free of any rotational or vibrational energy.

The process of forming a monatomic silver wire. Organic molecular wires have been proposed for use in optoelectronics.

The journal's scope includes all types of liquids, from monatomic liquids and their mixtures, through charged liquids to molecular liquids.

At 75 GPa it changes to a face-centered orthorhombic structure. At 100 GPa it changes to a body centered orthorhombic monatomic form.

The palladium membrane is typically a metallic tube of a palladium and silver alloy material possessing the unique property of allowing only monatomic hydrogen to pass through its crystal lattice when it is heated above 300°C.

Different gases will have different mean free paths for molecules and electrons. This is because different molecules have different diameters. Noble gases like helium and argon are monatomic and tend to have smaller diameters. This gives them greater mean free paths.

Fluoride (). According to this source, is a possible pronunciation in British English. is an inorganic, monatomic anion with the chemical formula (also written ), whose salts are typically white or colorless. Fluoride salts typically have distinctive bitter tastes, and are odorless.

Smaller-scale cloud features have been emphasized and a bluish hue has been applied to show that it was taken through a violet filter. Sulfuric acid is produced in the upper atmosphere by the Sun's photochemical action on carbon dioxide, sulfur dioxide, and water vapour. Ultraviolet photons of wavelengths less than 169 nm can photodissociate carbon dioxide into carbon monoxide and monatomic oxygen. Monatomic oxygen is highly reactive; when it reacts with sulfur dioxide, a trace component of the Venusian atmosphere, the result is sulfur trioxide, which can combine with water vapour, another trace component of Venus's atmosphere, to yield sulfuric acid.

As noted, the much lower values for gas heat capacity in terms of volume as compared with solids (although more comparable per mole, see below) results mostly from the fact that gases under standard conditions consist of mostly empty space (about 99.9% of volume), which is not filled by the atomic volumes of the atoms in the gas. Since the molar volume of gases is very roughly 1000 times that of solids and liquids, this results in a factor of about 1000 loss in volumetric heat capacity for gases, as compared with liquids and solids. Monatomic gas heat capacities per atom (not per molecule) are decreased by a factor of 2 with regard to solids, due to loss of half of the potential degrees of freedom per atom for storing energy in a monatomic gas, as compared with regard to an ideal solid. There is some difference in the heat capacity of monatomic vs.

Nascent Iodine sometimes known by the generic term atomic iodine or generic trademark name Atomidine or by the misname detoxified iodine, is a liquid orally administered supplemental form of iodine, claimed to be in the monatomic state, originating from a 1931 Edgar Cayce formula.

If hydrogen gas were monatomic and oxygen diatomic, the gas volume ratio would be 4:1. The volumetric composition of water is the ratio by volume of hydrogen to oxygen present. This value is 2:1 experimentally; this value is determined using Hofmann's water voltameter.

Iodide is one of the largest monatomic anions. It is assigned a radius of around 206 picometers. For comparison, the lighter halides are considerably smaller: bromide (196 pm), chloride (181 pm), and fluoride (133 pm). In part because of its size, iodide forms relatively weak bonds with most elements.

Monatomic fluids, e.g. molten sodium, have no chemical bonds to break and no crystal lattice to disturb, so they are immune to the chemical effects of ionizing radiation. Simple diatomic compounds with very negative enthalpy of formation, such as hydrogen fluoride will reform rapidly and spontaneously after ionization.

Two parallel monatomic sulfur chains grown inside a single-wall carbon nanotube (CNT, a). Zig-zag (b) and straight (c) S chains inside double-wall CNTs. Polysulfides are a class of chemical compounds containing chains of sulfur atoms. There are two main classes of polysulfides: anions and organic polysulfides.

The latter is what makes the sharpness button so important. When not in use, the sword is placed in a specially-designed scabbard which hold the sword using magnetic fields without actually touching it. A wound from a monatomic sword is nearly painless. These swords are extremely popular throughout the galaxy.

The monatomic sword (called by the protagonist "the plane sword") is an ideal melee weapon. Its blade is one atom thick. Due to such sharp blade, the sword can cut through any known material. Any strike or even a wave with the sword blunts the blade, making it thicker than one atom.

The oxidation state of the metal is shown as superscripted Roman numerals, whereas the charge of the entire complex is shown by the angle symbol together with the magnitude and sign of the net charge. Monatomic ions are sometimes also denoted with Roman numerals, particularly in spectroscopy; for example, the example seen above is occasionally referred to as Fe() or Fe, where the Roman numeral is the neutral state, and all ionizations are one numeral greater than the standard number. The Roman numeral designates the formal oxidation state of an element, whereas the superscripted Indo-Arabic numerals denote the net charge. The two notations are, therefore, exchangeable for monatomic ions, but the Roman numerals cannot be applied to polyatomic ions.

The only chemical elements that are stable diatomic homonuclear molecules at STP are hydrogen (H2), nitrogen (N2), oxygen (O2), and two halogens: fluorine (F2) and chlorine (Cl2). When grouped together with the monatomic noble gases - helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn) - these gases are called "elemental gases".

Structure of a classical monatomic liquid. Atoms have many nearest neighbors in contact, yet no long-range order is present. A liquid is a nearly incompressible fluid that conforms to the shape of its container but retains a (nearly) constant volume independent of pressure. The volume is definite if the temperature and pressure are constant.

Two parallel monatomic sulfur chains grown inside a single-wall carbon nanotube (CNT, a) Zig-zag (b) and straight (c) S chains inside double-wall CNTs. The production of pure forms of catena-sulfur has proved to be extremely difficult. Complicating factors include the purity of the starting material and the thermal history of the sample.

Structure of a classical monatomic liquid. Atoms have many nearest neighbors in contact, yet no long-range order is present. In a liquid, atoms do not form a crystalline lattice, nor do they show any other form of long-range order. This is evidenced by the absence of Bragg peaks in X-ray and neutron diffraction.

A theoretical understanding of temperature in a hard sphere model of a gas can be obtained from the Kinetic theory. Maxwell and Boltzmann developed a kinetic theory that yields a fundamental understanding of temperature in gases. This theory also explains the ideal gas law and the observed heat capacity of monatomic (or 'noble') gases.Balescu, R. (1975).

Partly protects the wearer from a monatomic sword. After a sword strike, it stretches over the wound and holds it in place. A wound of one atom thick heals in about 3 seconds (as long as the suit does not let it move). To neutralize the effect of the suit, the protagonist developed a "persistent sharpening" mode.

Typically, monatomic oxygen plasma is created by exposing oxygen gas at a low pressure (O2) to high power radio waves, which ionise it. This process is done under vacuum in order to create a plasma. As the plasma is formed, many free radicals are created which could damage the wafer. Newer, smaller circuitry is increasingly susceptible to these particles.

As compared to hydrogen bonding, the halogen atom takes the place of the partially positively charged hydrogen as the electrophile. Halogen bonding should not be confused with halogen–aromatic interactions, as the two are related but differ by definition. Halogen–aromatic interactions involve an electron-rich aromatic π-cloud as a nucleophile; halogen bonding is restricted to monatomic nucleophiles.

This is a list of known oxidation states of the chemical elements, excluding nonintegral values. The most common states appear in bold. The table is based on that of Greenwood and Earnshaw, with additions noted. Every element exists in oxidation state 0 when it is the pure non-ionized element in any phase, whether monatomic or polyatomic allotrope.

Working with David Nelson and Marco Ronchetti, Steinhardt formulated mathematical expressions, known as "orientational order parameters", for computing the degree of alignment of interatomic bonds in liquids and solids in 1981. Applying them to computer simulations of monatomic supercooled liquids, they showed that the atoms form arrangements with finite- range icosahedral (soccer-ball like) bond orientational order as liquids cool.

The thermopause is the atmospheric boundary of Earth's energy system, located at the top of the thermosphere. The temperature of the thermopause could range from nearly absolute zero to . Below this, the atmosphere is defined to be active on the insolation received, due to the increased presence of heavier gases such as monatomic oxygen. The solar constant is thus expressed at the thermopause.

Defects due to both external and intrinsic factors may appear. External factors include the cleanliness of the substrate, method of preparation, and purity of the adsorbates. SAMs intrinsically form defects due to the thermodynamics of formation, e.g. thiol SAMs on gold typically exhibit etch pits (monatomic vacancy islands) likely due to extraction of adatoms from the substrate and formation of adatom-adsorbate moieties.

In semiconductor manufacturing plasma ashing is the process of removing the photoresist (light sensitive coating) from an etched wafer. Using a plasma source, a monatomic (single atom) substance known as a reactive species is generated. Oxygen or fluorine are the most common reactive species. The reactive species combines with the photoresist to form ash which is removed with a vacuum pump.

A thermodynamic system is described by a number of thermodynamic parameters (e.g. temperature, volume, or pressure) which are not necessarily independent. The number of parameters needed to describe the system is the dimension of the state space of the system (). For example, a monatomic gas with a fixed number of particles is a simple case of a two- dimensional system ().

Spectral bands are part of optical spectra of polyatomic systems, including condensed materials, large molecules, etc. Each line corresponds to one level in the atom splits in the molecules. When the number of atoms is large, one gets a continuum of energy levels, the so-called "spectral bands". They are often labeled in the same way as the monatomic lines.

Gold is extremely ductile. It can be drawn into a monatomic wire, and then stretched more before it breaks. Ductility is especially important in metalworking, as materials that crack, break or shatter under stress cannot be manipulated using metal-forming processes such as hammering, rolling, drawing or extruding. Malleable materials can be formed cold using stamping or pressing, whereas brittle materials may be cast or thermoformed.

For mass spectrometry studies at low pressure, methenium can be obtained by ultraviolet photoionization of methyl radical, or by collisions of monatomic cations such as and with neutral methane. In such conditions, it will react with acetonitrile to form the ion . Upon capture of a low-energy electron (less than ), it will spontaneously dissociate. It is seldom encountered as an intermediate in the condensed phase.

Therefore, it would require more energy to hold the two atoms together through the antibonding orbital. Each electron in the valence 1s shell of hydrogen come together to fill in the stabilizing bonding orbital. So, hydrogen prefers to exist as a diatomic, and not monatomic, molecule. The MO diagram for helium When looking at helium, the atom holds two electrons in each valence 1s shell.

When the two atomic orbitals come together, they first fill in the bonding orbital with two electrons, but unlike hydrogen, it has two electrons left, which must then go to the antibonding orbital. The instability of the antibonding orbital cancels out the stabilizing effect provided by the bonding orbital; therefore, dihelium's bond order is 0. This is why helium would prefer to be monatomic over diatomic.

Neon discharge tube Neon is the chemical element with atomic number 10, occurring as 20Ne, 21Ne and 22Ne. Neon is a monatomic gas. With a complete octet of outer electrons it is highly resistant to removal of any electron, and it cannot accept an electron from anything. Neon has no tendency to form any normal compounds under normal temperatures and pressures; it is effectively inert.

Decaborane has no significant applications, although the compound has often been investigated. Since the molecule decomposes in a plasma, yielding monatomic boron ions, decaborane is potentially useful as a fuel for aneutronic fusion. In 2018, LPP Fusion announced plans for using the material in its next round of fusion experiments. Decaborane has been assessed for low energy ion implantation of boron in the manufacture of semiconductors.

Simple salts of the type M2X, where X is a monatomic anion, are not typically soluble in any solvent because they have a high lattice energy. Upon addition of water - even moist air - or treatment with alcohols, Te2− protonates: :Na2Te + H2O -> NaHTe + NaOH Because of this reaction, many processes attributed to Na2Te may involve NaHTe (CAS # 65312-92-7), which is more soluble and formed readily.

On the periodic table, homologous elements share many electrochemical properties and appear in the same group (column) of the table. For example, all noble gases are colorless, monatomic gases with very low reactivity. These similarities are due to similar structure in their outer shells of valence electrons. Mendeleev used the prefix eka- for an unknown element below a known one in the same group.

61 and occasionally as a metal. Unlike its lighter congener iodine, evidence for diatomic astatine is sparse and inconclusive.Merinis, Legoux & Bouissières 1972; Kugler & Keller 1985, pp. 110, 116, 210–211, 224; Takahashi & Otozai 1986; Zuckerman & Hagen 1989, pp. 21–22 (21); Takahashi, Yano & Baba 1992 In 2013, on the basis of relativistic modelling, astatine was predicted to be a monatomic metal, with a face-centered cubic crystalline structure.

In general, the number of these degrees of freedom that are available for the equipartitioning of energy depends on the temperature, i.e. the energy region of the interactions under consideration. For solids, the thermal energy is associated primarily with the vibrations of its atoms or molecules about their equilibrium position. In an ideal monatomic gas, the kinetic energy is found exclusively in the purely translational motions of the particles.

Educated in Budapest, he wrote his doctoral thesis on the chemical constant of monatomic gases. After teaching in a high school, he became an assistant professor in applied physics at the University of Sciences and accomplished valuable theoretical work investigating specific heat and molecular heat. From 1920 he worked with Max Born as assistant to the professor in Göttingen. They jointly worked out the dynamic theory of crystals.

Monatomic solids at room temperatures have approximately the same specific heat of 3k per atom, but at low temperatures they don't. The specific heat is smaller at colder temperatures, and it goes to zero at absolute zero. This is true for all material systems, and this observation is called the third law of thermodynamics. Classical mechanics cannot explain the third law, because in classical mechanics the specific heat is independent of the temperature.

For monatomic gases, such as the noble gases, the agreement with experiment is fairly good.Chapman & Cowling, pp. 249-251 For gases whose molecules are not spherically symmetric, the expression k = f \mu c_v still holds. In contrast with spherically symmetric molecules, however, f varies significantly depending on the particular form of the interparticle interactions: this is a result of the energy exchanges between the internal and translational degrees of freedom of the molecules.

Given a thermodynamic system at an absolute temperature , the average thermal energy carried by each microscopic degree of freedom in the system is (i.e., about , or , at room temperature). In classical statistical mechanics, this average is predicted to hold exactly for homogeneous ideal gases. Monatomic ideal gases (the six noble gases) possess three degrees of freedom per atom, corresponding to the three spatial directions, which means a thermal energy of per atom.

125x125pxSilylones are a class of zero-valent monatomic silicon complexes, characterized as having two lone pairs and two donor-acceptor ligand interactions stabilizing a silicon(0) center. Synthesis of silylones generally involves the use of sterically bulky carbenes to stabilize highly reactive Si(0) centers. For this reason, silylones are sometimes referred to siladicarbenes. To date, silylones have been synthesized with cyclic alkyl amino carbenes (cAAC) and bidentate N-heterocyclic carbenes (bis-NHC).

The temperature of an ideal monatomic gas is proportional to the average kinetic energy of its atoms. The size of helium atoms relative to their spacing is shown to scale under 1950 atmospheres of pressure. The atoms have a certain, average speed, slowed down here two trillion fold from room temperature. The kinetic theory of gases is a historically significant, but simple, model of the thermodynamic behavior of gases, with which many principal concepts of thermodynamics were established.

In the kinetic-molecular picture, a non-zero bulk viscosity arises in gases whenever there are non-negligible relaxational timescales governing the exchange of energy between the translational energy of molecules and their internal energy, e.g. rotational and vibrational. As such, the bulk viscosity is 0 for a monatomic ideal gas, in which the internal energy of molecules in negligible, but is nonzero for a gas like carbon dioxide, whose molecules possess both rotational and vibrational energy.

Monatomic caesium halide wires grown inside double-wall carbon nanotubes (TEM image). Caesium fluoride (CsF) is a hygroscopic white solid that is widely used in organofluorine chemistry as a source of fluoride anions. Caesium fluoride has the halite structure, which means that the Cs+ and F− pack in a cubic closest packed array as do Na+ and Cl− in sodium chloride. Notably, caesium and fluorine have the lowest and highest electronegativities, respectively, among all the known elements.

The equation of state given here (PV=nRT) applies only to an ideal gas, or as an approximation to a real gas that behaves sufficiently like an ideal gas. There are in fact many different forms of the equation of state. Since the ideal gas law neglects both molecular size and inter molecular attractions, it is most accurate for monatomic gases at high temperatures and low pressures. The neglect of molecular size becomes less important for lower densities, i.e.

When tin is combined with an alkali or alkaline earth metal some of the compounds formed have ionic structures containing monatomic or polyatomic tin anions (Zintl ions), such as Sn4− in Mg2SnS.M. Kauzlarich,(1994), Zintl Compounds, Encyclopedia of Inorganic Chemistry, John Wiley & sons, or in K4Sn9. Even with these metals not all of the compounds formed can be considered to be ionic with localised bonding, for example Sr3Sn5, a metallic compound, contains {Sn5} square pyramidal units.

CDWs are also common at the surface of solids where they are more commonly called surface reconstructions or even dimerization. Surfaces so often support CDWs because they can be described by two-dimensional Fermi surfaces like those of layered materials. Chains of Au and In on semiconducting substrates have been shown to exhibit CDWs. More recently, monatomic chains of Co on a metallic substrate were experimentally shown to exhibit a CDW instability and was attributed to ferromagnetic correlations.

Monatomic caesium halide wires grown inside double-wall carbon nanotubes. Bulk caesium iodide crystals have the cubic CsCl crystal structure, but the structure type of nanometer-thin CsI films depends on the substrate material – it is CsCl for mica and NaCl for LiF, NaBr and NaCl substrates. Caesium iodide atomic chains can be grown inside double-wall carbon nanotubes. In such chains I atoms appear brighter than Cs atoms in electron micrographs despite having a smaller mass.

HabashiHabashi 2010 groups the elements into eight major categories: [1] typical metals (alkali metals, alkaline earth metals, and aluminium); [2] lanthanides (Ce–Lu); [3] actinides (Th–Lr); [4] transition metals (Sc, Y, La, Ac, groups 4–10); [5] less typical metals (groups 11–12, Ga, In, Tl, Sn and Pb); [6] metalloids (B, Si, Ge, As, Se, Sb, Te, Bi and Po); [7] covalent nonmetals (H, C, N, O, P, S and the halogens); and [8] monatomic nonmetals (that is, the noble gases).

Niobium diselenide or niobium(IV) selenide is a layered transition metal dichalcogenide with formula NbSe2. Niobium diselenide is a lubricant, and a superconductor at temperatures below 7.2 K that exhibit a charge density wave (CDW). NbSe2 crystallizes in several related forms, and can be mechanically exfoliated into monatomic layers, similar to other transition metal dichalcogenide monolayers. Monolayer NbSe2 exhibits very different properties from the bulk material, such as of Ising superconductivity, quantum metallic state, and strong enhancement of the CDW.

The kinetic theory assumes that pressure is caused by the force associated with individual atoms striking the walls, and that all energy is translational kinetic energy. Using a sophisticated symmetry argument, Boltzmann deduced what is now called the Maxwell–Boltzmann probability distribution function for the velocity of particles in an ideal gas. From that probability distribution function, the average kinetic energy (per particle) of a monatomic ideal gas isTolman, R.C. (1938). The Principles of Statistical Mechanics, Oxford University Press, London, pp.

1950, p. 173 In 2013, on the basis of relativistic modelling, astatine was predicted to be a monatomic metal, with a face-centred cubic crystalline structure.Hermann, Hoffmann & Ashcroft 2013 Several authors have commented on the metallic nature of some of the properties of astatine. Since iodine is a semiconductor in the direction of its planes, and since the halogens become more metallic with increasing atomic number, it has been presumed that astatine would be a metal if it could form a condensed phase.

See also Group (periodic table). Neon is a colorless, odorless, inert monatomic gas under standard conditions, with about two-thirds the density of air. It was discovered (along with krypton and xenon) in 1898 as one of the three residual rare inert elements remaining in dry air, after nitrogen, oxygen, argon and carbon dioxide were removed. Neon was the second of these three rare gases to be discovered and was immediately recognized as a new element from its bright red emission spectrum.

The study of liquid and glass structure aims to gain insight into their behavior and physical properties, so that they can be understood, predicted and tailored for specific applications. Since the structure and resulting behavior of liquids and glasses is a complex many body problem, historically it has been too computationally intensive to solve using quantum mechanics directly. Instead, a variety of diffraction, NMR, Molecular dynamics, and Monte Carlo simulation techniques are most commonly used. Structure of a classical monatomic liquid.

Other monovalent anions that have been studied include nitrate, nitrite and azide. Ion pairs of monatomic anions, such as halide ions, cannot be studied by this technique. NMR spectroscopy is not very useful, as association/dissociation reactions tend to be fast on the NMR time scale, giving time-averaged signals of the cation and/or anion. Nearly the same shift of vibration frequency is observed for solvent-shared ion pairs of LiCN, Be(CN)2 and Al(CN)3 in liquid ammonia.

Dr. Haraburda made significant contributions into optimizing the engineering designs of spacecraft propulsion and heat exchangers. In the early 1990s, he conducted research on a Microwave Electrothermal Thruster, to which he developed a simple equilibrium based theory of space-dependent parameters for transport design equations, using helium as the monatomic gas and nitrogen as the diatomic gas. In the mid-1990s, Dr. Haraburda also designed Helical-coil heat exchangers for fluids with components in multiple phases (solids, liquids, and gases).

The most common type of indirectly heated cathode is the oxide-coated cathode, in which the nickel cathode surface has a coating of alkaline earth metal oxide to increase emission. One of the earliest materials used for this was barium oxide; it forms a monatomic layer of barium with an extremely low work function. More modern formulations utilize a mixture of barium oxide, strontium oxide and calcium oxide. Another standard formulation is barium oxide, calcium oxide, and aluminium oxide in a 5:3:2 ratio.

The bond in a homonuclear diatomic molecule is non-polar. A periodic table showing the elements that exist as homonuclear diatomic molecules under typical laboratory conditions. The only chemical elements that form stable homonuclear diatomic molecules at standard temperature and pressure (STP) (or typical laboratory conditions of 1 bar and 25 °C) are the gases hydrogen (H2), nitrogen (N2), oxygen (O2), fluorine (F2), and chlorine (Cl2). The noble gases (helium, neon, argon, krypton, xenon, and radon) are also gases at STP, but they are monatomic.

Enthalpy of atomization is the amount of enthalpy change when a compound's bonds are broken and the component atoms are reduced to individual atoms. Enthalpy of atomization is denoted by the symbol ΔatH. The enthalpy change of atomization of gaseous H2O is, for example, the sum of the HO–H and H–O bond dissociation enthalpies. The enthalpy of atomization of an elemental solid is exactly the same as the enthalpy of sublimation for any elemental solid that becomes a monatomic gas upon evaporation.

In atmospheric chemistry, a null cycle is a catalytic cycle that simply interconverts chemical species without leading to net production or removal of any component. In the stratosphere, null cycles and when the null cycles are broken are very important to the ozone layer. One of the most important null cycles takes place in the stratosphere, with the photolysis of ozone by photons with wavelengths less than 330 nanometers. This photolysis produces a monatomic oxygen that then reacts with the diatomic oxygen producing ozone.

According to the nomenclature recommended by IUPAC, ionic compounds are named according to their composition, not their structure. In the most simple case of a binary ionic compound with no possible ambiguity about the charges and thus the stoichiometry, the common name is written using two words. The name of the cation (the unmodified element name for monatomic cations) comes first, followed by the name of the anion. For example, MgCl2 is named magnesium chloride, and Na2SO4 is named sodium sulfate (, sulfate, is an example of a polyatomic ion).

Maxwell at the Chemical Society on 18 February 1875. since atoms have internal parts, heat energy should go into the motion of these internal parts, making the predicted specific heats of monatomic and diatomic gases much higher than 3 cal/(mol·K) and 7 cal/(mol·K), respectively. A third discrepancy concerned the specific heat of metals. According to the classical Drude model, metallic electrons act as a nearly ideal gas, and so they should contribute (3/2) NekB to the heat capacity by the equipartition theorem, where Ne is the number of electrons.

In other words, the ability to convert thermal energy into work while the rubber relaxes is allowed by the higher entropy of the relaxed state. The result is that a rubber band behaves somewhat like an ideal monatomic gas inasmuch as (to good approximation) that elastic polymers do not store any potential energy in stretched chemical bonds. No elastic work is done to "stretch" molecules when work is done upon these bulk polymers. Instead, all work done to the rubber is "released" (not stored) and appears immediately in the polymer as thermal energy.

A sketch of Robert John Strutt when he was old can also be found in Young (1982). (Please see reference.) In 1910 Robert Strutt discovered that an electrical discharge in nitrogen gas produced "active nitrogen", an allotrope considered to be monatomic. The "whirling cloud of brilliant yellow light" produced by his apparatus reacted with quicksilver to produce explosive mercury nitride. In 1916, working with his colleague Alfred Fowler, Strutt was the first to prove the existence of ozone in the atmosphere by examining the ultra-violet spectrum of the setting sun.

Thus a diatomic gas will require more energy input to increase its temperature by a certain amount, i.e. it will have a greater heat capacity than a monatomic gas. As noted above, the speed of sound in a gas can be calculated from the molecular character of the gas, from its temperature and pressure, and from the value of Boltzmann's constant. Taking the value of Boltzmann's constant as a primarily defined reference of exactly defined value, a measurement of the speed of sound can provide a more precise measurement of the temperature of the gas.

In this mechanical interpretation of thermal motion, the kinetic energies of material particles may reside in the velocity of the particles of their translational or vibrational motion or in the inertia of their rotational modes. In monatomic perfect gases and, approximately, in most gases, temperature is a measure of the mean particle kinetic energy. It also determines the probability distribution function of the energy. In condensed matter, and particularly in solids, this purely mechanical description is often less useful and the oscillator model provides a better description to account for quantum mechanical phenomena.

The atom and the radical ion are isoelectronic because each has five electrons in the outer electronic shell. Similarly, same number of valence electrons, same structure and same number of atoms the cations , , and and the anions , , and are all isoelectronic with the atom. In such monatomic cases, there is a clear trend in the sizes of such species, with atomic radius decreasing as charge increases. CO, , , , and are isoelectronic because each has two nuclei and 10 valence electrons, with each atom considered to have 5 of them (a lone-pair and a triple-bond).

The main difference between the two processes is the temperature the wafer is exposed to while in an ashing chamber. Monatomic oxygen is electrically neutral and although it does recombine during the channeling, it does so at a slower rate than the positively or negatively charged free radicals, which attract one another. This means that when all of the free radicals have recombined, there is still a portion of the active species available for process. Because a large portion of the active species is lost to recombination, process times may take longer.

Other dipole induction mechanisms also exist in molecular (as opposed to monatomic) gases and in mixtures of gases, when molecular gases are present. Molecules have centers of positive charge (the nuclei), which are surrounded by a cloud of electrons. Molecules thus may be thought of being surrounded by various electric multipolar fields which will polarize any collisional partner momentarily in a fly-by encounter, generating the so- called multipole-induced dipoles. In diatomic molecules such as H2 and N2, the lowest-order multipole moment is the quadrupole, followed by a hexadecapole, etc.

Although krypton and xenon can be also used; argon is favorable because of its low cost. The light generated by an explosion is produced primarily by compression heating of the surrounding air. Replacement of the air with a noble gas considerably increases the light output; with molecular gases, the energy is consumed partially by dissociation and other processes, while noble gases are monatomic and can only undergo ionization; the ionized gas then produces the light. The low specific heat capacity of noble gases allows heating to higher temperatures, yielding brighter emission.

Monatomic ions are formed by the gain or loss of electrons to the valence shell (the outer-most electron shell) in an atom. The inner shells of an atom are filled with electrons that are tightly bound to the positively charged atomic nucleus, and so do not participate in this kind of chemical interaction. The process of gaining or losing electrons from a neutral atom or molecule is called ionization. Atoms can be ionized by bombardment with radiation, but the more usual process of ionization encountered in chemistry is the transfer of electrons between atoms or molecules.

Interpretation of carbon isotope effects are usually complicated by simultaneously forming and breaking bonds to carbon. Even reactions that involve only bond cleavage from the carbon, such as SN1 reactions, involve strengthening of the remaining bonds to carbon. In many such reactions, leaving group isotope effects tend to be easier to interpret. For example, substitution and elimination reactions in which chlorine act as a leaving group are convenient to interpret, especially since chlorine acts as a monatomic species with no internal bonding to complicate the reaction coordinate, and it has two stable isotopes, 35Cl and 37Cl, both with high abundance.

The absorption spectrum of astatine in the middle ultraviolet region has lines at 224.401 and 216.225 nm, suggestive of 6p to 7s transitions. The structure of solid astatine is unknown. As an analogue of iodine it may have an orthorhombic crystalline structure composed of diatomic astatine molecules, and be a semiconductor (with a band gap of 0.7 eV). Alternatively, if condensed astatine forms a metallic phase, as has been predicted, it may have a monatomic face-centered cubic structure; in this structure it may well be a superconductor, like the similar high-pressure phase of iodine.

The chemistry of astatine is "clouded by the extremely low concentrations at which astatine experiments have been conducted, and the possibility of reactions with impurities, walls and filters, or radioactivity by-products, and other unwanted nano-scale interactions". Many of its apparent chemical properties have been observed using tracer studies on extremely dilute astatine solutions, typically less than 10−10 mol·L−1. Some properties, such as anion formation, align with other halogens. Astatine has some metallic characteristics as well, such as plating onto a cathode, coprecipitating with metal sulfides in hydrochloric acid, and forming a stable monatomic cation in aqueous solution.

Radon is a colorless, odorless, and tasteless gas and therefore is not detectable by human senses alone. At standard temperature and pressure, radon forms a monatomic gas with a density of 9.73 kg/m3, about 8 times the density of the Earth's atmosphere at sea level, 1.217 kg/m3. Radon is one of the densest gases at room temperature and is the densest of the noble gases. Although colorless at standard temperature and pressure, when cooled below its freezing point of , radon emits a brilliant radioluminescence that turns from yellow to orange-red as the temperature lowers.

Heat capacity is a measurable physical quantity equal to the ratio of the heat added to an object to the resulting temperature change. The molar heat capacity is the heat capacity per unit amount (SI unit: mole) of a pure substance, and the specific heat capacity, often called simply specific heat, is the heat capacity per unit mass of a material. Heat capacity is a physical property of a substance, which means that it depends on the state and properties of the substance under consideration. The specific heats of monatomic gases, such as helium, are nearly constant with temperature.

Experimental observations of the specific heat capacities of gases also raised concerns about the validity of the equipartition theorem. The theorem predicts that the molar heat capacity of simple monatomic gases should be roughly 3 cal/(mol·K), whereas that of diatomic gases should be roughly 7 cal/(mol·K). Experiments confirmed the former prediction, but found that molar heat capacities of diatomic gases were typically about 5 cal/(mol·K), and fell to about 3 cal/(mol·K) at very low temperatures. Maxwell noted in 1875 that the disagreement between experiment and the equipartition theorem was much worse than even these numbers suggest; A lecture delivered by Prof.

Because of their opposite electric charges, cations and anions attract each other and readily form ionic compounds. Ions consisting of only a single atom are termed atomic or monatomic ions, while two or more atoms form molecular ions or polyatomic ions. In the case of physical ionization in a fluid (gas or liquid), "ion pairs" are created by spontaneous molecule collisions, where each generated pair consists of a free electron and a positive ion. Ions are also created by chemical interactions, such as the dissolution of a salt in liquids, or by other means, such as passing a direct current through a conducting solution, dissolving an anode via ionization.

The above equation is a good approximation only when the argument of the logarithm is much larger than unity – the concept of an ideal gas breaks down at low values of . Nevertheless, there will be a "best" value of the constant in the sense that the predicted entropy is as close as possible to the actual entropy, given the flawed assumption of ideality. A quantum- mechanical derivation of this constant is developed in the derivation of the Sackur–Tetrode equation which expresses the entropy of a monatomic ( = ) ideal gas. In the Sackur–Tetrode theory the constant depends only upon the mass of the gas particle.

One of the first quantum effects to be explicitly noticed (but not understood at the time) was a Maxwell observation involving hydrogen, half a century before full quantum mechanical theory arrived. Maxwell observed that the specific heat capacity of H2 unaccountably departs from that of a diatomic gas below room temperature and begins to increasingly resemble that of a monatomic gas at cryogenic temperatures. According to quantum theory, this behavior arises from the spacing of the (quantized) rotational energy levels, which are particularly wide-spaced in H2 because of its low mass. These widely spaced levels inhibit equal partition of heat energy into rotational motion in hydrogen at low temperatures.

Many properties of promethium rely on its position among lanthanides and are intermediate between those of neodymium and samarium. For example, the melting point, the first three ionization energies, and the hydration energy are greater than those of neodymium and lower than those of samarium; similarly, the estimate for the boiling point, ionic (Pm3+) radius, and standard heat of formation of monatomic gas are greater than those of samarium and less than those of neodymium. Promethium has a double hexagonal close packed (dhcp) structure and a hardness of 63 kg/mm2. This low- temperature alpha form converts into a beta, body-centered cubic (bcc) phase upon heating to 890 °C.

Helium discharge tube Helium (He) is a colorless, odorless, tasteless, non-toxic, inert monatomic chemical element that heads the noble gas series in the periodic table and whose atomic number is 2. Its boiling and melting points are the lowest among the elements and it exists only as a gas except in extreme conditions. Helium was discovered in 1868 by French astronomer Pierre Janssen, who first detected the substance as an unknown yellow spectral line signature in light from a solar eclipse. In 1903, large reserves of helium were found in the natural gas fields of the United States, which is by far the largest supplier of the gas.

The noble gases (historically also the inert gases; sometimes referred to as aerogens) make up a class of chemical elements with similar properties; under standard conditions, they are all odorless, colorless, monatomic gases with very low chemical reactivity. The six naturally occurring noble gases are helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and the radioactive radon (Rn). Oganesson (Og) is variously predicted to be a noble gas as well or to break the trend due to relativistic effects; its chemistry has not yet been investigated. For the first six periods of the periodic table, the noble gases are exactly the members of group 18\.

Large complex gas molecules may have high heat capacities per mole (of molecules), but their heat capacities per mole of atoms are very similar to those of liquids and solids, again differing by less than a factor of two per mole of atoms. This factor of two represents vibrational degrees of freedom available in solids vs. gas molecules of various complexities. In monatomic gases (like argon) at room temperature and constant volume, volumetric heat capacities are all very close to 0.5kJ/K/m3, which is the same as the theoretical value of RT per kelvin per mole of gas molecules (where R is the gas constant and T is temperature).

At high pressures, helium also causes high-pressure nervous syndrome, which is a central nervous system irritation syndrome which is in some ways opposite to narcosis. Helium mixture fills are considerably more expensive than air fills due to the cost of helium and the cost of mixing and compressing the mix. Helium is not suitable for dry suit inflation owing to its poor thermal insulation properties – compared to air, which is regarded as a reasonable insulator, helium has six times the thermal conductivity. Helium's low molecular weight (monatomic MW=4, compared with diatomic nitrogen MW=28) increases the timbre of the breather's voice, which may impede communication.

Like the virial theorem, it gives the total average kinetic and potential energies for a system at a given temperature, from which the system's heat capacity can be computed. However, equipartition also gives the average values of individual components of the energy, such as the kinetic energy of a particular particle or the potential energy of a single spring. For example, it predicts that every atom in a monatomic ideal gas has an average kinetic energy of (3/2)kBT in thermal equilibrium, where kB is the Boltzmann constant and T is the (thermodynamic) temperature. More generally, equipartition can be applied to any classical system in thermal equilibrium, no matter how complicated.

The major constituents of Earth's atmosphere, nitrogen ()(78%), oxygen ()(21%), and argon (Ar)(0.9%), are not greenhouse gases because molecules containing two atoms of the same element such as and have no net change in the distribution of their electrical charges when they vibrate, and monatomic gases such as Ar do not have vibrational modes. Hence they are almost totally unaffected by infrared radiation. Some molecules containing just two atoms of different elements, such as carbon monoxide (CO) and hydrogen chloride (HCl), do absorb infrared radiation, but these molecules are short-lived in the atmosphere owing to their reactivity or solubility. Therefore, they do not contribute significantly to the greenhouse effect and often are omitted when discussing greenhouse gases.

Others believed the spectral lines could belong to an element that occurred on the Sun but not Earth; some believed it was yet to be found on Earth. In 1894, British chemist William Ramsay and British physicist Lord Rayleigh isolated argon from air and determined that it was a new element. Argon, however, did not engage in any chemical reactions and was—highly unusually for a gas—monatomic; it did not fit into the periodic law and thus challenged the very notion of it. Not all scientists immediately accepted this report; Mendeleev's original response to that was that argon was a triatomic form of nitrogen rather than an element of its own.

The most celebrated discoveries of Scottish chemist William Ramsay were made in inorganic chemistry. Ramsay was intrigued by the British physicist John Strutt, 3rd Baron Rayleigh's 1892 discovery that the atomic weight of nitrogen found in chemical compounds was lower than that of nitrogen found in the atmosphere. He ascribed this discrepancy to a light gas included in chemical compounds of nitrogen, while Ramsay suspected a hitherto undiscovered heavy gas in atmospheric nitrogen. Using two different methods to remove all known gases from air, Ramsay and Lord Rayleigh were able to announce in 1894 that they had found a monatomic, chemically inert gaseous element that constituted nearly 1 percent of the atmosphere; they named it argon.

It also shows some metallic behavior, including being able to form a stable monatomic cation in aqueous solution (unlike the lighter halogens). The first synthesis of the element was in 1940 by Dale R. Corson, Kenneth Ross MacKenzie, and Emilio G. Segrè at the University of California, Berkeley, who named it from the Greek astatos (ἄστατος), meaning "unstable". Four isotopes of astatine were subsequently found to be naturally occurring, although much less than one gram is present at any given time in the Earth's crust. Neither the most stable isotope astatine-210, nor the medically useful astatine-211, occur naturally; they can only be produced synthetically, usually by bombarding bismuth-209 with alpha particles.

Diatomic elements played an important role in the elucidation of the concepts of element, atom, and molecule in the 19th century, because some of the most common elements, such as hydrogen, oxygen, and nitrogen, occur as diatomic molecules. John Dalton's original atomic hypothesis assumed that all elements were monatomic and that the atoms in compounds would normally have the simplest atomic ratios with respect to one another. For example, Dalton assumed water's formula to be HO, giving the atomic weight of oxygen as eight times that of hydrogen, instead of the modern value of about 16. As a consequence, confusion existed regarding atomic weights and molecular formulas for about half a century.

Its exact definition also varied over the years due to redefinitions of the kelvin (see ) and other SI base units (see ). In 2017, the most accurate measures of the Boltzmann constant were obtained by acoustic gas thermometry, which determines the speed of sound of a monatomic gas in a triaxial ellipsoid chamber using microwave and acoustic resonances. This decade-long effort was undertaken with different techniques by several laboratories; it is one of the cornerstones of the 2019 redefinition of SI base units. Based on these measurements, the CODATA recommended 1.380 649 × 10−23 J⋅K−1 to be the final fixed value of the Boltzmann constant to be used for the International System of Units.

Molecular motion in condensed matter can be represented by a Fourier series whose physical interpretation consists of a superposition of longitudinal and transverse waves of atomic displacement with varying directions and wavelengths. In monatomic systems, these waves are called density fluctuations. (In polyatomic systems, they may also include compositional fluctuations.)Slater, J.C., Introduction to Chemical Physics (3rd Ed., Martindell Press, 2007) Thus, thermal motion in liquids can be decomposed into elementary longitudinal vibrations (or acoustic phonons) while transverse vibrations (or shear waves) were originally described only in elastic solids exhibiting the highly ordered crystalline state of matter. In other words, simple liquids cannot support an applied force in the form of a shearing stress, and will yield mechanically via macroscopic plastic deformation (or viscous flow).

When the alkali metals react with the heavier elements in the carbon group (silicon, germanium, tin, and lead), ionic substances with cage- like structures are formed, such as the silicides M4Si4 (M = K, Rb, or Cs), which contains M+ and tetrahedral ions. The chemistry of alkali metal germanides, involving the germanide ion Ge4− and other cluster (Zintl) ions such as , , , and [(Ge9)2]6−, is largely analogous to that of the corresponding silicides. Alkali metal stannides are mostly ionic, sometimes with the stannide ion (Sn4−), and sometimes with more complex Zintl ions such as , which appears in tetrapotassium nonastannide (K4Sn9). The monatomic plumbide ion (Pb4−) is unknown, and indeed its formation is predicted to be energetically unfavourable; alkali metal plumbides have complex Zintl ions, such as .

The MO diagram for dihydrogen In the classic example of the H2 MO, the two separate H atoms have identical atomic orbitals. When creating the molecule dihydrogen, the individual valence orbitals, 1s, either: merge in phase to get bonding orbitals, where the electron density is in between the nuclei of the atoms; or, merge out of phase to get antibonding orbitals, where the electron density is everywhere around the atom except for the space between the nuclei of the two atoms. Bonding orbitals lead to a more stable species than when the two hydrogens are monatomic. Antibonding orbitals are less stable because, with very little to no electron density in the middle, the two nuclei (holding the same charge) repulse each other.

The Sackur–Tetrode equation is an expression for the entropy of a monatomic ideal gas. It is named for Hugo Martin TetrodeH. Tetrode (1912) "Die chemische Konstante der Gase und das elementare Wirkungsquantum" (The chemical constant of gases and the elementary quantum of action), Annalen der Physik 38: 434–442. See also: H. Tetrode (1912) "Berichtigung zu meiner Arbeit: "Die chemische Konstante der Gase und das elementare Wirkungsquantum" " (Correction to my work: "The chemical constant of gases and the elementary quantum of action"), Annalen der Physik 39: 255–256. (1895–1931) and Otto SackurSackur published his findings in the following series of papers: # O. Sackur (1911) "Die Anwendung der kinetischen Theorie der Gase auf chemische Probleme" (The application of the kinetic theory of gases to chemical problems), Annalen der Physik, 36: 958–980.

Avogadro's hypothesis began to gain broad appeal among chemists only after his compatriot and fellow scientist Stanislao Cannizzaro demonstrated its value in 1858, two years after Avogadro's death. Cannizzaro's chemical interests had originally centered on natural products and on reactions of aromatic compounds; in 1853 he discovered that when benzaldehyde is treated with concentrated base, both benzoic acid and benzyl alcohol are produced—a phenomenon known today as the Cannizzaro reaction. In his 1858 pamphlet, Cannizzaro showed that a complete return to the ideas of Avogadro could be used to construct a consistent and robust theoretical structure that fit nearly all of the available empirical evidence. For instance, he pointed to evidence that suggested that not all elementary gases consist of two atoms per molecule—some were monatomic, most were diatomic, and a few were even more complex.

This charge is often small, because matter is made of atoms, and atoms typically have equal numbers of protons and electrons, in which case their charges cancel out, yielding a net charge of zero, thus making the atom neutral. An ion is an atom (or group of atoms) that has lost one or more electrons, giving it a net positive charge (cation), or that has gained one or more electrons, giving it a net negative charge (anion). Monatomic ions are formed from single atoms, while polyatomic ions are formed from two or more atoms that have been bonded together, in each case yielding an ion with a positive or negative net charge. During the formation of macroscopic objects, constituent atoms and ions usually combine to form structures composed of neutral ionic compounds electrically bound to neutral atoms.

25 ml of bromine, a dark red-brown liquid at room temperature Nonmetals have open structures (unless solidified from gaseous or liquid forms); tend to gain or share electrons when they react with other substances; and do not form distinctly basic oxides. Most are gases at room temperature; have relatively low densities; are poor electrical and thermal conductors; have relatively high ionisation energies and electronegativities; form acidic oxides; and are found naturally in uncombined states in large amounts. Some nonmetals (C, black P, S and Se) are brittle solids at room temperature (although each of these also have malleable, pliable or ductile allotropes). From left to right in the periodic table, the nonmetals can be subdivided into the reactive nonmetals which, being nearest to the metalloids, show some incipient metallic character, and the monatomic noble gases, which are almost completely inert.

In these cases, a generalized compressibility chart or an alternative equation of state better suited to the problem must be utilized to produce accurate results. A related situation occurs in hypersonic aerodynamics, where dissociation causes an increase in the “notional” molar volume, because a mole of oxygen, as O2, becomes 2 moles of monatomic oxygen and N2 similarly dissociates to 2 N. Since this occurs dynamically as air flows over the aerospace object, it is convenient to alter , defined for an initial 30 gram moles of air, rather than track the varying mean molecular weight, millisecond by millisecond. This pressure dependent transition occurs for atmospheric oxygen in the 2,500–4,000 K temperature range, and in the 5,000–10,000 K range for nitrogen. In transition regions, where this pressure dependent dissociation is incomplete, both beta (the volume/pressure differential ratio) and the differential, constant pressure heat capacity greatly increases.

The 1s1 electron configuration of hydrogen, while superficially similar to that of the alkali metals (ns1), is unique because there is no 1p subshell. Hence it can lose an electron to form the hydron H+, or gain one to form the hydride ion H−. In the former case it resembles superficially the alkali metals; in the latter case, the halogens, but the differences due to the lack of a 1p subshell are important enough that neither group fits the properties of hydrogen well. Group 14 is also a good fit in terms of thermodynamic properties such as ionisation energy and electron affinity, but hydrogen cannot be tetravalent. Thus none of the three placements are entirely satisfactory, although group 1 is the most common placement (if one is chosen) because the hydron is by far the most important of all monatomic hydrogen species, being the foundation of acid-base chemistry.

Link to Web site. The only metals with enthalpies of fusion not in the range of 6–30 J mol−1 K−1 are (on the high side): Ta, W, and Re; and (on the low side) most of the group 1 (alkaline) metals plus Ga, In, Hg, Tl, Pb, and Np. Citation: This link to Web Elements' home page. If the substance is one of the monatomic gases, (which have little tendency to form molecular bonds) the heat of fusion is more modest, ranging from 0.021 to 2.3 kJ per mole.Xenon value citation: This link to WebElements' xenon data (available values range from 2.3 to 3.1 kJ/mol). It is also noteworthy that helium's heat of fusion of only 0.021 kJ/mol is so weak of a bonding force that zero-point energy prevents helium from freezing unless it is under a pressure of at least 25 atmospheres.

Returning to the United States in 1928, Eckart was appointed Assistant Professor in the Physics Department at the University of Chicago, where he continued his work on quantum mechanics for another 14 years. Noteworthy was a paper co-authored with Helmut Hönl, who received his doctorate under Sommerfeld in 1926; the paper, on the foundations of quantum mechanics, dealt with the role of group theory in quantum dynamics in monatomic systems and comparisons of the nuclear theories of Werner Heisenberg and Eugene Wigner. During this period, Eckart developed his formulation of the Wigner-Eckart theorem – a link between symmetry transformation groups applied to the Schrödinger equation and the laws of conservation of energy, momentum, and angular momentum. The theorem is particularly useful in spectroscopy. With F. C. Hoyt, Eckart translatedWerner Heisenberg, Translated by Carl Eckart and F. C. Hoyt The Physical Principles of the Quantum Theory (Dover, 1930) Heisenberg’s book on the physical principles of quantum mechanics.

Its relative rarity on Earth, like that of helium, is due to its relative lightness, high vapor pressure at very low temperatures, and chemical inertness, all properties which tend to keep it from being trapped in the condensing gas and dust clouds that formed the smaller and warmer solid planets like Earth. Blue Neon sign in a pastry shop Neon is monatomic, making it lighter than the molecules of diatomic nitrogen and oxygen which form the bulk of Earth's atmosphere; a balloon filled with neon will rise in air, albeit more slowly than a helium balloon. Neon's abundance in the universe is about 1 part in 750; in the Sun and presumably in the proto-solar system nebula, about 1 part in 600. The Galileo spacecraft atmospheric entry probe found that even in the upper atmosphere of Jupiter, the abundance of neon is reduced (depleted) by about a factor of 10, to a level of 1 part in 6,000 by mass.