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Sulfur Mononitride
Sulfur mononitride is an inorganic compound with the molecular formula SN. It is the sulfur analogue of and isoelectronic to the radical nitric oxide, NO. It was initially detected in 1975, in outer space in giant molecular clouds and later the coma of comets. This spurred further laboratory studies of the compound. Synthetically, it is produced by electric discharge in mixtures of nitrogen and sulfur compounds, or combustion in the gas phase and by photolysis in solution. Synthesis The NS radical is a highly transient species, with a lifetime on the order of milliseconds, but it can be observed spectroscopically over short periods of time through several methods of generation. NS is too reactive to isolate as a solid or liquid, and has only been prepared as a vapor in low pressure or low-temperature matrices due to its tendency to rapidly oligomerize to more stable, diamagnetic species. Discharge of nitrogen and sulfur vapor Transmission of electric discharge through a glass ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inorganic Compound
An inorganic compound is typically a chemical compound that lacks carbon–hydrogen bondsthat is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as ''inorganic chemistry''. Inorganic compounds comprise most of the Earth's crust, although the compositions of the deep Mantle (geology), mantle remain active areas of investigation. All allotropes (structurally different pure forms of an element) and some simple carbon compounds are often considered inorganic. Examples include the allotropes of carbon (graphite, diamond, buckminsterfullerene, graphene, etc.), carbon monoxide , carbon dioxide , carbides, and salt (chemistry), salts of inorganic anions such as carbonates, cyanides, cyanates, thiocyanates, isothiocyanates, etc. Many of these are normal parts of mostly organic systems, including organisms; describing a chemical as inorganic does not necessarily mean that it cannot occur within life, living things. History ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X-ray Crystallography
X-ray crystallography is the experimental science of determining the atomic and molecular structure of a crystal, in which the crystalline structure causes a beam of incident X-rays to Diffraction, diffract in specific directions. By measuring the angles and intensities of the X-ray diffraction, a crystallography, crystallographer can produce a three-dimensional picture of the density of electrons within the crystal and the positions of the atoms, as well as their chemical bonds, crystallographic disorder, and other information. X-ray crystallography has been fundamental in the development of many scientific fields. In its first decades of use, this method determined the size of atoms, the lengths and types of chemical bonds, and the atomic-scale differences between various materials, especially minerals and alloys. The method has also revealed the structure and function of many biological molecules, including vitamins, drugs, proteins and nucleic acids such as DNA. X-ray crystall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Comet Hyakutake
Comet Hyakutake (Astronomical naming conventions#Comets, formally designated C/1996 B2) is a comet discovered on 31 January 1996. It was dubbed the Great Comet of 1996; its passage to within of the Earth on 25 March was one of the closest cometary approaches of the previous 200 years. Reaching an apparent visual magnitude of zero and spanning nearly 80°, Hyakutake appeared very bright in the night sky and was widely seen around the world. The comet temporarily upstaged the much anticipated Comet Hale–Bopp, which was approaching the inner Solar System at the time. Hyakutake is a Comet#Orbital characteristics, long-period comet that passed perihelion on 1 May 1996. Before its most recent passage through the Solar System, its orbital period was about 17,000 years, but the gravitational Perturbation (astronomy), perturbation of the giant planets has increased this period to 70,000 years. This is the first comet to have an X-ray emission detected, which is most likely th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Giant Molecular Clouds
A molecular cloud—sometimes called a stellar nursery if star formation is occurring within—is a type of interstellar cloud of which the density and size permit absorption nebulae, the formation of molecules (most commonly molecular hydrogen, H2), and the formation of H II regions. This is in contrast to other areas of the interstellar medium that contain predominantly ionized gas. Molecular hydrogen is difficult to detect by infrared and radio observations, so the molecule most often used to determine the presence of H2 is carbon monoxide (CO). The ratio between CO luminosity and H2 mass is thought to be constant, although there are reasons to doubt this assumption in observations of some other galaxies. Within molecular clouds are regions with higher density, where much dust and many gas cores reside, called clumps. These clumps are the beginning of star formation if gravitational forces are sufficient to cause the dust and gas to collapse. Research and discovery The h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Radio Astronomy Observatory
The National Radio Astronomy Observatory (NRAO) is a federally funded research and development center of the United States National Science Foundation operated under cooperative agreement by Associated Universities, Inc. for the purpose of radio astronomy. NRAO designs, builds, and operates its own high-sensitivity radio telescopes for use by scientists around the world. Locations Charlottesville, Virginia The NRAO headquarters is located on the campus of the University of Virginia in Charlottesville, Virginia. The North American ALMA Science Center and the NRAO Technology Center and Central Development Laboratory are also in Charlottesville. Green Bank, West Virginia NRAO was, until October 2016, the operator of the world's largest fully steerable radio telescope, the Robert C. Byrd Green Bank Telescope, which stands near Green Bank, West Virginia. The observatory contains several other telescopes, among them the telescope that utilizes an equatorial mount uncommon for ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sagittarius B2
Sagittarius B2 (Sgr B2) is a giant molecular cloud of gas and dust that is located about from the center of the Milky Way. This complex is the largest molecular cloud in the vicinity of the core and one of the largest in the galaxy, spanning a region about across. The total mass of Sgr B2 is about 3 million times the mass of the Sun. The mean hydrogen density within the cloud is 3000 atoms per cm3, which is about 20–40 times denser than a typical molecular cloud. The internal structure of this cloud is complex, with varying densities and temperatures. The cloud is divided into three main cores, designated north (N), middle or main (M) and south (S) respectively. Thus Sgr B2(N) represents the north core. The sites Sgr B2(M) and Sgr B2(N) are sites of prolific star formation. The first 10 H II regions discovered were designated A through J. H II regions A–G, I and J lie within Sgr B2(M), while region K is in Sgr B2(N) and region H is in Sgr B2(S). The 5-parsec-wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electronegativity
Electronegativity, symbolized as , is the tendency for an atom of a given chemical element to attract shared electrons (or electron density) when forming a chemical bond. An atom's electronegativity is affected by both its atomic number and the distance at which its valence electrons reside from the charged nucleus. The higher the associated electronegativity, the more an atom or a substituent group attracts electrons. Electronegativity serves as a simple way to quantitatively estimate the bond energy, and the sign and magnitude of a bond's chemical polarity, which characterizes a bond along the continuous scale from covalent to ionic bonding. The loosely defined term electropositivity is the opposite of electronegativity: it characterizes an element's tendency to donate valence electrons. On the most basic level, electronegativity is determined by factors like the nuclear charge (the more protons an atom has, the more "pull" it will have on electrons) and the number and lo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Orbital Of NS
A molecule is a group of two or more atoms that are held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions that satisfy this criterion. In quantum physics, organic chemistry, and biochemistry, the distinction from ions is dropped and ''molecule'' is often used when referring to polyatomic ions. A molecule may be homonuclear, that is, it consists of atoms of one chemical element, e.g. two atoms in the oxygen molecule (O2); or it may be heteronuclear, a chemical compound composed of more than one element, e.g. water (two hydrogen atoms and one oxygen atom; H2O). In the kinetic theory of gases, the term ''molecule'' is often used for any gaseous particle regardless of its composition. This relaxes the requirement that a molecule contains two or more atoms, since the noble gases are individual atoms. Atoms and complexes connected by non-covalent interactions, such as hydrogen bonds or ionic bonds, are typically not ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Resonance Structure Of NS
Resonance is a phenomenon that occurs when an object or system is subjected to an external force or vibration whose frequency matches a resonant frequency (or resonance frequency) of the system, defined as a frequency that generates a maximum amplitude response in the system. When this happens, the object or system absorbs energy from the external force and starts vibrating with a larger amplitude. Resonance can occur in various systems, such as mechanical, electrical, or acoustic systems, and it is often desirable in certain applications, such as musical instruments or radio receivers. However, resonance can also be detrimental, leading to excessive vibrations or even structural failure in some cases. All systems, including molecular systems and particles, tend to vibrate at a natural frequency depending upon their structure; when there is very little damping this frequency is approximately equal to, but slightly above, the resonant frequency. When an oscillating force, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Resonance Structure
In chemistry, resonance, also called mesomerism, is a way of describing bonding in certain molecules or polyatomic ions by the combination of several contributing structures (or ''forms'', also variously known as ''resonance structures'' or ''canonical structures'') into a resonance hybrid (or ''hybrid structure'') in valence bond theory. It has particular value for analyzing delocalized electrons where the bonding cannot be expressed by one single Lewis structure. The resonance hybrid is the accurate structure for a molecule or ion; it is an average of the theoretical (or hypothetical) contributing structures. Overview Under the framework of valence bond theory, resonance is an extension of the idea that the bonding in a chemical species can be described by a Lewis structure. For many chemical species, a single Lewis structure, consisting of atoms obeying the octet rule, possibly bearing formal charges, and connected by bonds of positive integer order, is sufficient for des ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbital Bonding Picture Of NS
Orbital may refer to: Sciences Chemistry and physics * Atomic orbital * Molecular orbital * Hybrid orbital Astronomy and space flight * Orbit ** Earth orbit Medicine and physiology * Orbit (anatomy), also known as the ''orbital bone'' * Orbitofrontal cortex, a part of the brain used for decision making Business * Orbital Corporation, an Australian engine technology company * Orbital Sciences Corporation, a U.S. satellite launch and defense systems corporation * Orbital ATK, American aerospace manufacturer formed from the merger of Orbital Sciences Corporation and parts of Alliant Techsystems Transportation * Ring road (or ''orbital road'' in some regions) * Orbital (metro), a rapid transit line usually encircling a city centre * Orbital engine Other uses * ''Orbital'' (novel), a 2023 novel by Samantha Harvey * Orbital (The Culture), artificial worlds from Iain M. Banks's series of science fiction novels, the Culture * Orbital (band), an English electronic dance music duo, who ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HOMO And LUMO
In chemistry, HOMO and LUMO are types of molecular orbitals. The acronyms stand for ''highest occupied molecular orbital'' and ''lowest unoccupied molecular orbital'', respectively. HOMO and LUMO are sometimes collectively called the ''frontier orbitals'', such as in the frontier molecular orbital theory. Gap The energy difference between the HOMO and LUMO is ''the HOMO–LUMO gap''. Its size can be used to predict the strength and stability of transition metal complexes, as well as the colors they produce in solution. As a rule of thumb, the smaller a compound's HOMO–LUMO gap, the less stable the compound. Recent quantum‐chemical analyses of over 700 compounds demonstrated that terrestrial secondary metabolites exhibit HOMO–LUMO gaps on average about 2 eV narrower than organic molecules found in carbonaceous meteorites, and that combining gap width with hydrophilicity creates a robust discriminator between biotic and abiotic chemistries. This suggests that the HOMO–LUM ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
