for examples of things measuring between one and ten picometres 1 picometre File Atom.svg thumb right A simplified representation of a helium atom, having an estimated calculated radius of 31 picometres ref name WebElementsSize cite web url http www.webelements.com periodicity atomic radius title Atomic radius work WebElements the periodic table on the web ref A picometre symbol pm is a Units of measurement unit of length in the metric system , equal to one trillionth, i.e. sup 1 sup sub 1,000,000,000,000 sub of a metre , which is the current International System of Units SI SI base unit base unit of length. It can be written in scientific notation as 1× 10 sup &minus 12 sup m, or as nowrap 1 E 12 m in engineering notation both meaning nowrap 1 m 1,000,000,000,000 . It equals a millionth of a micrometre formerly called a micron , and was formerly called micromicron, stigma, or bicron. ref cite book title Dictionary of Distances first1 Elena last1 Deza first2 Michel Marie last2 Deza author2 link Michel Deza publisher Elsevier year 2006 isbn 0444520872 url http books.google.com books?id I PQH8gcOjUC&pg PA347&dq stigma bicron ref The symbol was once used for it. ref How Many? A Dictionary of Units of Measurement Russ Rowlett and the University of North Carolina at Chapel Hill http www.unc.edu rowlett units dictB.html ref It is also a hundredth of an angstrom , an internationally recognised but non SI unit of length. The picometre s length is of an order such that its application is almost entirely confined to particle physics and quantum physics . Atom s are between 62 and 520 pm in diameter. Smaller units still may be used to describe smaller particles some of which are the components of atoms themselves , such as hadron s and the upper limits of possible size for fermion point particles. The Laser Interferometer Space Antenna Science Laser Interferometer Space Antenna LISA probe currently planned to be launched in 2025 to directly detect gravitational ... more details
To help compare different orders of magnitude s this page lists length s between 10 sup 9 sup metre s and 10 sup 8 sup metres 1 nanometre s and 10 nanometres . 1 E 10 m Distances shorter than 1 nanometre 1 nm 1 nanometre 1000 picometre s 10 angstrom s 1 nm rough length of a sucrose molecule, as calculated by Albert Einstein Citation needed date December 2008 1.1 nm diameter of a single walled carbon nanotube Citation needed date February 2009 2 nm diameter of DNA helix ref cite web last Stewart first Robert title Dr. url http rh.healthsciences.purdue.edu vc theory dna index.html work Radiobiology Software accessdate 29 June 2011 ref 3.4 nm length of a DNA Turn biochemistry turn 10 Base pair bp Citation needed date February 2009 3 8 nm size of an Albumins albumin protein molecule Citation needed date February 2009 6.8 nm width of a haemoglobin molecule Citation needed date February 2009 7.5 nm thickness of a cell membrane 1 E 8 m Distances longer than 10 nanometres See also Nanoflower Associations Orders of magnitude length wide Notes Reflist External links cite book title Nanotechnology Overviews chapter A nano scale overview url http en.wikibooks.org wiki Nanotechnology Overviews A nano scale overview publisher Wikibooks accessdate 2009 02 21 when template is able to link to specific section modify and uncomment following wikibookspar Nanotechnology Introduction Clarify me date December 2008 the book really covers the scale at Nanotechnology Overviews A nano scale overview, but how to make the template cleanly interlink to it? DEFAULTSORT 1 Nanometre Category Orders of magnitude length 09 es Anexo 1 E 9 m eo 1 E 9 m fr 1 E 9 m it 1 E 9 m sl 1 E 9 m sh 1 E 9 m ... more details
About the real molecule fictional uses originating with Star Trek Dilithium Star Trek Chembox Verifiedfields changed verifiedrevid 458280126 ImageFileL1 Dilithium 2D dimensions.png ImageNameL1 Wireframe model of dilithium ImageFileR1 Dilithium 3D vdW.png ImageNameR1 Spacefill model of dilithium IUPACName Dilithium Section1 Chembox Identifiers CASNo 14452 59 6 CASNo Ref cascite changed ?? PubChem 139759 PubChem Ref Pubchemcite correct PubChemcite ChemSpiderID 123254 ChemSpiderID Ref chemspidercite correct chemspider SMILES Li Li StdInChI Ref stdinchicite correct chemspider StdInChI 1S 2Li StdInChIKey Ref stdinchicite correct chemspider StdInChIKey SMBQBQBNOXIFSF UHFFFAOYSA N Section2 Chembox Properties Li 2 ExactMass 14.032008098 g mol sup 1 sup Dilithium , Li sub 2 sub , is a diatomic molecule comprising two lithium atom s covalent bond covalently bonded together. Li sub 2 sub is known in the gas Phase matter phase . It has a bond order of 1, an internuclear separation of 267.3 picometre pm and a bond energy of 101 kJ mol sup 1 sup . ref Chemical Bonding , Mark J. Winter, Oxford University Press, 1994 , ISBN 0 19 855694 2 ref See also MO diagram Dilithium MO diagram Dilithium molecular orbital diagram References reflist Further reading Greenwood&Earnshaw Category Lithium de Dilithium fr Dilithium ko it Litio Dilitio nl Dilithium scheikunde ... more details
To help compare different orders of magnitude this page lists length s between 10 sup 10 sup metre m and 10 sup 9 sup m 100 picometre pm and 1 nanometre nm . 1 E 11 m Distances shorter than 100 pm 100 pm 1 angstrom 100 pm covalent radius of sulfur atom ref cite web author Mark Winter title WebElements Periodic Table of the Elements Sulfur Radii url http www.webelements.com sulfur atom sizes.html date 2008 accessdate 2008 12 06 ref 120 pm van der Waals radius of a neutral hydrogen atom ref cite web author Mark Winter title WebElements Periodic Table of the Elements Periodicity Van der Waals radius periodicity url http www.webelements.com periodicity van der waals radius date 2008 accessdate 2008 12 06 ref 126 pm covalent radius of ruthenium atom 135 pm covalent radius of technetium atom 153 pm covalent radius of silver atom 154 pm mode length of carbon C C covalent bond 155 pm covalent radius of zirconium atom 175 pm covalent radius of thulium atom 200 pm highest resolution of a typical electron microscope ref cite web title Resolution of an Electron Microscope BOT GENERATED TITLE url http hypertextbook.com facts 2000 IlyaSherman.shtml work archiveurl http www.webcitation.org 5gOzHewWJ archivedate 2009 04 29 deadurl no accessdate 2009 04 25 ref 225 pm covalent radius of caesium atom 340 pm thickness of single layer graphene 356.68 pm width of diamond cell unit cell 403 pm width of lithium fluoride cell 500 pm width of alpha helix helix protein 560 pm width of sodium chloride cell 700 pm width of glucose molecule 780 pm mean width of quartz cell 820 pm mean width of ice cell 900 pm mean width of coesite cell 900 pm width of sucrose molecule 1 E 9 m Distances longer than 1 nm See also Associations Orders of magnitude length wide Notes reflist DEFAULTSORT 100 Picometres Category Orders of magnitude length 10 es Anexo 1 E 10 m fr 1 E 10 m ko 1 E 10 m it 1 E 10 m hu 1 E 10 m simple 1 E 10 m sk 1 E 10 m sl 1 E 10 m sh 1 E 10 m ta 1 E 10 m th 1 E 10 m ... more details
for examples of things measuring between one and ten femtometres 1 femtometre The femtometre American spelling femtometer , symbol fm Danish language Danish lang da femten , fifteen Ancient Greek lang grc , lang grc Latn metr n , unit of measurement is an SI unit of length equal to 10 sup 15 sup metre s. This distance can also be called fermi and was so named in honour of Enrico Fermi and is often encountered in nuclear physics as a characteristic of this scale. The symbol for the fermi is also fm ref http metricsystemconversion.info fermi to femtometer fm.html?func detail ref ref http www.unc.edu rowlett units dictF.html ref ref http www.hep.phys.soton.ac.uk hepwww staff D.Ross phys3002 diffraction.pdf ref . Definition 1 femtometre 1.0 x 10 sup 15 sup metres 1 fermi 0.001 picometre 1000 attometres 1,000,000 femtometres 1 nanometre. For an example of lengths in this unit, the diameter of a gold Atomic nucleus nucleus is approximately 8.45 femtometres. citation needed date April 2011 History The femtometre was adopted by the 11th Conf rence G n rale des Poids et Mesures, and added to SI in 1964. The fermi is named after the Italy Italian physicist Enrico Fermi 1901 1954 , one of the founders of nuclear physics. The term was coined by Robert Hofstadter in a 1956 paper published in the Reviews of Modern Physics journal, Electron Scattering and Nuclear Structure ref http rmp.aps.org abstract RMP v28 i3 p214 1 Hofstadter, Robert, Department of Physics, Stanford University, Stanford, California, Electron Scattering and Nuclear Structure, Rev. Mod. Phys. 28, 214 254 1956 1956 The American Physical Society ref . The term is widely used by nuclear and particle physics particle physicists. When Hofstadter was awarded the 1961 Nobel Prize in Physics, it subsequently appears in the text of his 1961 Nobel Lecture, The electron scattering method and its application to the structure of nuclei and nucleons December 11, 1961 . ref http nobelprize.org nobel prizes physics laur ... more details
Unreferenced date September 2009 TOC right Many different units of length have been used across the world. The main units in modern use are U.S. customary units in the United States and the Metric system elsewhere. British Imperial unit s are still used for some purposes in the United Kingdom and some other countries. The metric system is sub divided into International System of Units SI and non SI units. Metric system main Metric system SI units main International System of Units Common units of length in the International System of Units SI are metre and its multiples, such as centimetre or kilometre Non SI units Non SI units of length include fermi fm 1 femtometre in SI units angstrom 100 picometre s in SI units micron 1 micrometre in SI units Norwegian Swedish mil 10,000 metres Imperial US units main Imperial unit main U.S. customary units Common Imperial units and U.S. customary units of length include inch 2.54 cm mil one thousandth of an inch, one thou unit of length thou foot length foot 12 inches, 0.3048 m yard 3 ft, 0.9144 m terrestrial mile 5280 ft, 1609.344 m Marine In addition, the following are used by mariners fathom for depth only in non metric countries 2 yards 1.8288 m nautical mile one minute of arc of latitude 1852 m Aviation Aviators use feet same as US for altitude worldwide except in Russia and China. Surveying Surveyor surveying Surveyor s in the United States continue to use chain unit chain 20.1m rod unit rod also called pole or perch 5 m Astronomical main Astronomical system of units Astronomy Astronomical measure uses Earth radius RE 6,370 km astronomical unit AU 150 gigametres light year ly 9.46 petametres parsec pc 30.8 petametres , including kiloparsec kpc and megaparsec Mpc Archaic units main Ancient weights and measures Archaic units of distance include cana unit of length cana cubit Rope unit Rope league unit league Li unit li China Pace unit of length pace the double pace of about 5 feet used in Ancient R ... more details
Gold clusters in cluster chemistry are gold derived materials that can either be discrete molecules or larger colloid al particles. Both types are describes as nanoparticles , with diameters of less than one micrometer. Discrete gold clusters Well defined, molecular clusters are known, invariably containing organic ligand s on their exteriors. Two examples are Au sub 6 sub carbide C Triphenylphosphine P C sub 6 sub H sub 5 sub sub 3 sub sub 6 sub sup 2 sup and Au sub 9 sub P C sub 6 sub H sub 5 sub sub 3 sub sub 8 sub sup 3 sup . ref Holleman, A. F. Wiberg, E. Inorganic Chemistry Academic Press San Diego, 2001. ISBN 0 12 352651 5. ref Colloidal clusters Gold clusters can be obtained in colloidal gold colloid form . Such colloids often occur with a surface coating of alkanethiol s or protein s. Such clusters can be used in immunohistochemical staining . ref Hainfeld, J. F. Powell, R. D. New Frontiers in Gold Labeling The Journal of Histochemistry & Cytochemistry, 2000 ,Volume 48, pages 471 480, http www.histochem.org archives new 20frontiers 20gold 20labeling2000.pdf Online Article ref Gold Gold metal nanoparticles NPs are characterized by an intense absorption in the visible spectrum visible region, which enhances the utility of these species for the development of completely optical devices. The wavelength of this surface plasmon resonance SPR band depends on the size and shape of the nanoparticles as well as their interactions with the surrounding medium. The presence of this band enhances the utility of gold nanoparticle as building blocks for devices for data storage, ultrafast switching, and gas sensors. Gas phase clusters Evidence has been presented for the existence of hollow golden cages with the partial formula Au sub n sub sup sup with n 16 to 18. ref Evidence of Hollow Golden Cages Bulusu, S. Li, X. Wang, L. S. Zeng, X. C. Proc. Natl. Acad. Sci. USA 2006, http dx.doi.org 10.1073 pnas.0600637103 Abstract ref These cluster compounds with diameter of 550 pic ... more details
chembox verifiedrevid 408475059 ImageFileL1 Rhenium trioxide unit cell 3D balls B.png ImageFileR1 REO3.JPG ImageSize IUPACName Rhenium trioxide OtherNames Rhenia Section1 Chembox Identifiers CASNo 1314 28 9 PubChem SMILES Section2 Chembox Properties Formula ReO sub 3 sub MolarMass 234.205 Appearance Deep red crystals Density 6.92 g cm sup 3 sup MeltingPt 400 C decomposes BoilingPt Solubility RefractIndex 1.68 Section3 Chembox Structure CrystalStruct Cubic, Pearson symbol cP4 SpaceGroup P m span style text decoration overline 3 span m , SpaceGroup 221 Section7 Chembox Hazards MainHazards FlashPt Autoignition Image Rhenium trioxide 3D vdW.png thumb Image Rhenium trioxide polyhedra.png thumb ReO sub 3 sub polyhedra Rhenium trioxide rhenium VI oxide , ReO sub 3 sub is a red solid with a metallic lustre. It is the only stable oxide trioxide of the Group 7 elements Manganese Mn , Technetium Tc , Rhenium Re . Structure Rhenium oxide forms crystals with a Primitive cell primitive Cubic crystal system cubic Crystal structure unit cell , with a Crystal structure lattice parameter of 3.742 ngstr m 374.2 picometre pm . The structure of ReO sub 3 sub is similar to the Perovskite structure Perovskite structure ABO sub 3 sub , without the large A cation at the centre of the unit cell. Each rhenium atom is surrounded by six oxygen atoms, forming a ReO sub 6 sub octahedron . These octahedra share corners to form the 3 dimensional structure ref S.J. Heyes 2000 http www.ncl.ox.ac.uk icl heyes structure of solids Lecture4 Lec4.html anchor3 Structures of Simple Inorganic Solids , Department of Chemistry, University of Oxford. ref . Upon viewing a unit cell of ReO sub 3 sub , one can see that it is composed of eight fragments of rhenium atoms, and twelve fragments of oxygen atoms. These numbers reduce to 1 Re and 3 O, hence the formula of ReO sub 3 sub . The coordination number of Re in this compound is 6 because each rhenium atom has six neighbouring oxygen atoms which bear opposite ... more details
A vector magnetograph is a type of imaging telescope that can estimate the Three dimensional space 3 D vector geometric vector of the magnetic field on a distant body with a resolved line spectrum . Magnetographs are useful for studying the Sun because the surface magnetic field is important to the creation and maintenance of the solar corona , and gives rise to the phenomena of solar flare s and space weather . Vector magnetographs measure the longitudinal line of sight component of the magnetic field separately from the transverse image plane components, using different aspects of the Zeeman splitting that affects the wavelength of emission and or absorption spectral line s in the presence of a magnetic field. The Zeeman splitting is caused by the fact that individual atom s are magnetized due to the circulating motion of electron s bound to them. Emission or absorption of a photon changes the magnetic moment of the atom. In a magnetic field, photons emitted with different polarizations gain or lose energy depending on their orientation relative to the surrounding magnetic field, changing the characteristics of the spectral line some polarization components are blue shifted or red shifted relative to the line s reference wavelength , by a factor proportional to the field intensity. Specifically, the circular polarized component of the light is shifted in wavelength proportional to the field strength in the direction of the observer, and the wavelength shift of the vertical and horizontal linearly polarized components measures the field strength in those directions. A vector magnetograph works in a very narrow waveband around a single spectral line , for example the 525.02 nanometer nm Fe I line from neutral non ionized iron . The measured shifts in wavelength are fractions of a picometre . Measuring the full spectral profile of the line with this precision requires a high dispersion spectrograph and a long time to collect sufficient photon s to make the measuremen ... more details
The Dewar Chatt Duncanson model is a model in organometallic chemistry which explains the type of chemical bond ing between an alkene and a metal pi complex in certain organometallic compounds. The model is named after Michael J. S. Dewar , ref Dewar, M. Bull. Soc. Chim. Fr. 1951 , 1 8 , C79 ref Joseph Chatt and L. A. Duncanson . ref Olefin co ordination compounds. Part III. Infra red spectra and structure attempted preparation of acetylene complexes J. Chatt and L. A. Duncanson, J. Chem. Soc., 1953 , 2939 DOI 10.1039 JR9530002939 ref ref Directing effects in inorganic substitution reactions. Part I. A hypothesis to explain the trans effect J. Chatt, L. A. Duncanson, L. M. Venanzi, J. Chem. Soc., 1955 , 4456 4460 DOI 10.1039 JR9550004456 ref The pi acid alkene donates electron density into a metal d orbital from symmetry bonding orbital between the carbon atoms I . The metal donates electrons back from a different filled d orbital into the empty sup sup antibonding orbital II . Both of these effects tend to reduce the carbon carbon bond order, leading to an elongated C C distance and a lowering its vibrational frequency. Image Dewar Chatt Duncanson model.png 300px The Dewar Chatt Duncanson model I forward donation II backdonation In Zeise s salt K nowiki nowiki platinum Pt Cl sub 3 sub C sub 2 sub H sub 4 sub sup . sup H sub 2 sub O the C C bond length has increased to 134 picometre s from 133 pm for ethylene . In the nickel compound Ni CH sub 2 sub CH sub 2 sub PPh sub 3 sub sub 2 sub the value is 143 pm. The interaction also causes carbon atoms to rehybridise from Sp2 hybridization sp sup 2 sup towards Sp3 bond sp sup 3 sup , which is indicated by the bending of the hydrogen atoms on the ethylene back away from the metal. ref cite book last Miessler first Gary L. coauthors Donald A. Tarr year 2004 title Inorganic Chemistry publisher Pearson Education, Inc. Pearson Prentice Hall location Upper Saddle River, New Jersey isbn 0 13 035471 6 . ref In silico calculat ... more details
12 sup metres 1 pm 1 metre SI prefixed forms of metre picometre 1,000 metre SI prefixed forms of metre ..., femtometre, picometre Orders of magnitude length References Reflist Category Orders of magnitude ... more details
Image Dilatometer.jpg thumb A simple structure of a dilatometer for the measurement of the thermal expansion of liquids and solids A dilatometer is a scientific instrument that measures volume changes caused by a physical or chemical process. A familiar application of a dilatometer is the mercury in glass thermometer , in which the change in volume of the liquid column is read from a graduated scale. Because mercury has a fairly constant rate of expansion over normal temperature ranges, the volume changes are directly related to temperature. Applications Dilatometers have been used in the fabrication of metallic alloys, compressed and sinter ed refractory compounds, glasses, ceramic products, composite materials, and plastics. ref name Lehmann Hans Lehmann, refuge Gatzke Dilatometrie and differential thermal analysis for the evaluation of processes ? ? , 1956. ref Dilatometry is also used to monitor the progress of chemical reactions, particularly those displaying a substantial molar volume change e.g., polymerisation . A specific example is the rate of phase changes. ref cite journal author Kastle, J. H. coauthors Kelley, W. P. title On the Rate of Crystallization of Plastic Sulphur journal American Chemical Journal year 1904 month July volume 32 pages 483&ndash 503 url http books.google.com ?id OH0FAQAAIAAJ&pg PA497&dq dilatometer Kopp ref Another common application of a dilatometer is the measurement of thermal expansion . The thermal expansivity is defined as math alpha frac 1 V biggl frac delta V delta T biggr P math and is an important engineering parameter. Types There are a number of dilatometer types Capacity dilatometers possess a parallel plate capacitor with a one stationary plate, and one moveable plate. When the sample length changes, it moves the moveable plate, which changes the gap between the plates. The capacitance is inversely proportional to the gap. Changes in length of 10 picometre s can be detected. ref name neum J. J. Neumeier, R. K. Bolling ... more details
Infobox mineral name Roscoelite category Vanadium mineral, Phyllosilicate boxwidth boxbgcolor image imagesize caption Roscoelite formula K V sup 3 sup ,Al,Mg sub 2 sub AlSi sub 3 sub O sub 10 sub OH sub 2 sub molweight g mol color olive color olive green to green brown habit scales, fans, Druse geology druses , Rosette mineralogy rosette s, fibrous or felted aggregate. system Monoclinic 2 m twinning cleavage Perfect plane 0,0,1 fracture platy tenacity mohs 1 luster pearly polish refractive n 1.60 n 1.66 n 1.67 opticalprop Biaxial birefringence dispersion pleochroism olive green to green brown fluorescence absorption streak gravity 2.92 2.96 density fusibility loses water diagnostic diaphaneity semi transparent to translucent other references Roscoelite is a green mineral from the mica group that contains vanadium . The chemical formula is potassium K vanadium V sup 3 sup , aluminum Al , magnesium Mg sub 2 sub aluminum Al silicon Si sub 3 sub oxygen O sub 10 sub O hydrogen H sub 2 sub ref http rruff.geo.arizona.edu doclib hom roscoelite.pdf Roscoelite information ref . Crystals of roscoelite take on the monoclinic form, and are from the 2 m point group . The appearance is semi transparent to translucent coloured olive brown to green brown. The Lustre mineralogy luster is pearly. The mineral shows pleochroism with X showing green brown, and Y and Z axes showing olive green colour. The mineral was named after Henry Enfield Roscoe who first produced vanadium metal. Chemical properties Roscoelite is a muscovite with aluminium substituted with vanadium. Vanadium can also be substituted by magnesium , iron , or manganese . Physical properties It is soft and the density is 2.93 0.01. The unit cell has dimensions a 526 picometre pm b 909 pm c 1025 pm, with an angle between axes of 101.0 . The tetrahedral cation oxygen atom distance is 164.1 pm, The distance from the cation to the oxygen in the octahedral plan is 202 pm. ref http cat.inis ... more details
File Tetrafluoroammonium ion.png thumb 150px 2D model of the tetrafluoroammonium ion The tetrafluoroammonium ion cation also known as perfluoroammonium is a positively charged polyatomic ion with chemical formula chem NF 4 . It is equivalent to the ammonium ion where the hydrogen atoms surrounding the central nitrogen atom have been replaced by fluorine . ref cite doi 10.1070 RC1985v054n05ABEH003068 ref . Tetrafluoroammonium ion is isoelectronicity isoelectronic with tetrafluoromethane chem CF 4 and tetrafluoroborate chem BF 4 ion. The tetrafluoroammonium ion forms salt chemistry salts with a large variety of fluorine bearing anions. These include the bifluoride anion chem HF 2 , tetrafluorobromate chem BrF 4 , metal pentafluorides chem XF 5 where X is germanium Ge , tin Sn , or titanium Ti , hexafluorides chem XF 6 where X is phosphorus P , arsenic As , antimony Sb , bismuth Bi , or platinum Pt , heptafluorides chem XF 7 where X is tungsten W , uranium U , or xenon Xe , octafluorides chem XeF 8 2 , ref cite doi 10.1021 ic00142a001 ref various oxyfluorides chem XF 5 O where X is W or U chem link fluorosulfuric acid FSO 3 , chem BrF 4 O , and perchlorate chem ClO 4 . ref name karlchriste cite doi 10.1021 ic00231a038 ref Attempts to make the nitrate salt, chem NF 4 NO 3 , were unsuccessful because of quick fluorination chem NF 4 chem NO 3 chem NF 3 chem FONO 2 . ref name hoge cite doi 10.1016 S0022 1139 01 00415 8 ref Structure The geometry of the tetrafluoroammonium ion is tetrahedral molecular geometry tetrahedral , with an estimated nitrogen fluorine bond length of 124 Picometre pm . All fluorine atoms are in equivalent positions. ref name sykes1 Synthesis Tetrafluoroammonium salts are prepared by oxidising nitrogen trifluoride with fluorine in the presence of a strong Lewis acid which acts as a fluoride ion acceptor. The original synthesis by Tolberg, Rewick, Stringham, and Hill in 1966 employs antimony pentafluoride as the Lewis acid ref name sykes1 chem NF ... more details
i.e., point spread function , which can be as small as a few picometre s. Hence the ability to measure small local differences in object height like that of 135 picometre steps on 100 silicon is unparalleled ... more details
Wiktionary PM Pm pm p.m. TOC right PM also written P.M., p.m., and pm often means after noon in the 12 hour clock Latin Post meridiem . PM or Pm may also refer to Sciences Particulate matter, particulate s fine dust and soot suspended in the air PM10 , particulates, smaller than 10 m, that can cause health problems PM3 chemistry , or Parameterized Model number 3 a modelling method in computational chemistry Permanent magnet , an object which stays magnetised without external effort or mason. Perpetual motion , refers to movement that goes on forever Petameter , a length unit 10 sup 15 sup m Pm Phase modulation , in electrical engineering PM tube , Photomultiplier tube. Picometre , a length unit 10 sup 12 sup m pm Plasma membrane , is a selectively permeable lipid bilayer found in all cells Powdery mildew , a fungal disease that affects a wide range of plants Powder metallurgy , a method of fabricating metals. Premolar tooth, dental nomenclature Promethium , chemical element number 61 Pm Polymyositis , disease Post mortem , a medical examination carried out after death Principia Mathematica , a three volume work on the foundations of mathematics Polarization maintaining optical fiber Participatory medicine , a new model of medicine People P.M. author , an anonymous Swiss author P. M. Aboobacker , Indian Muslim political leader in Kerala P. M. Blau 1918 2002 , American sociologist and theorist see Peter Blau P. M. Cohn 1924 2006 , German born British mathematician Paul Cohn P.M. Daka, Zambian member of Pan African Parliament see Peter Daka P. M. Henry 1849 1903 , or Prosper Henry, French optician and astronomer see Paul Henry and Prosper Henry P. M. Hubbard 1910 1980 , British writer P. M. Kilmartin, New Zealand astronomer see Pamela M. Kilmartin P.M. McCullough 1893 1981 , American actor see Philo McCullough P. M. Pasinetti 1913 2006 , Italian novelist, professor and journalist P. M. Pu 1910 1988 , Chinese mathematician see Pao Ming Pu P. M. Radhakr ... more details
chembox verifiedrevid 445854534 Name Stibine ImageFileL1 Stibine.png ImageSizeL1 120px ImageNameL1 Stibine ImageFileR1 Stibine 3D vdW.png ImageSizeR1 120px ImageNameR1 Stibine IUPACName Stibane OtherNames Antimony trihydride Section1 Chembox Identifiers ChemSpiderID Ref chemspidercite correct chemspider ChemSpiderID 8992 InChI 1 Sb.3H rH3Sb h1H3 InChIKey OUULRIDHGPHMNQ LQMOCBGJAH ChEBI Ref ebicite correct EBI ChEBI 30288 SMILES Sb StdInChI Ref stdinchicite correct chemspider StdInChI 1S Sb.3H StdInChIKey Ref stdinchicite correct chemspider StdInChIKey OUULRIDHGPHMNQ UHFFFAOYSA N CASNo Ref cascite correct ?? CASNo 7803 52 3 Section2 Chembox Properties Formula H sub 3 sub Sb MolarMass 124.784 g mol Appearance Colourless gas Density 5.48 g L, gas Solvent other solvents SolubleOther Insoluble MeltingPtC 88 BoilingPtC 17 pKb Section3 Chembox Structure MolShape Trigonal pyramidal Dipole Section7 Chembox Hazards ExternalMSDS EUClass Harmful Xn br Dangerous for br the environment N NFPA H 4 NFPA R 2 NFPA F 4 RPhrases R20 22 R50 53 SPhrases S2 S61 FlashPt Flammable gas Section8 Chembox Related OtherCpds Ammonia , br Phosphine , br Arsine br Bismuthine br Triphenylstibine Stibine is the chemical compound with the formula SbH sub 3 sub . This colourless gas is the principal covalent hydride of antimony and a heavy analogue of ammonia . The molecule is pyramidal with H Sb H angles of 91.7 and Sb H distances of 1.707 Angstrom 170.7 picometre pm . This gas has an offensive smell like hydrogen sulfide rotten eggs . Preparation SbH sub 3 sub is generally prepared by the reaction of Sb sup 3 sup sources with H sup &minus sup equivalents ref cite journal author Bellama, J. M. MacDiarmid, A. G. title Synthesis of the Hydrides of Germanium, Phosphorus, Arsenic, and Antimony by the Solid Phase Reaction of the Corresponding Oxide with Lithium Aluminum Hydride journal Inorg. Chem. year 1968 volume 7 pages 2070 2 doi 10.1021 ic50068a024 issue 10 ref 2 Sb sub 2 sub O sub 3 sub 3 LiAlH sub ... more details
The Jahn Teller effect , sometimes also known as Jahn Teller distortion , or the Jahn Teller theorem , describes the geometrical distortion of non linear molecule s under certain situations. This electronic effect is named after Hermann Arthur Jahn and Edward Teller , who proved, using group theory , that orbital non linear spatially degenerate molecules cannot be stable. ref cite journal author Hermann Arthur Jahn H. Jahn and Edward Teller E. Teller title Stability of Polyatomic Molecules in Degenerate Electronic States. I. Orbital Degeneracy year 1937 journal Proceedings of the Royal Society of London. Series A, Mathematical and Physical Sciences 1934 1990 volume 161 issue 905 pages 220 235 doi 10.1098 rspa.1937.0142 bibcode 1937RSPSA.161..220J ref The theorem essentially states that any non linear molecule with a spatially degenerate energy level degenerate electronic ground state will undergo a geometrical distortion that removes that degeneracy, because the distortion lowers the overall energy of the complex. Transition metal chemistry Image Hexaaquacopper II 3D balls.png thumb right 220px The Jahn Teller effect is responsible for the tetragonal distortion of the hexaaquacopper II complex ion, Cu OH sub 2 sub sub 6 sub sup 2 sup , which might otherwise possess octahedral molecular geometry octahedral geometry. The two axial Cu O distances are 238 picometre pm , whereas the four equatorial Cu O distances are 195 pm. The Jahn Teller effect is most often encountered in octahedral complex es of the transition metals, and is very common in six coordinate copper II complexes. ref cite book title Metal ligand bonding author Rob Janes and Elaine A. Moore publisher Royal Society of Chemistry year 2004 isbn 0854049797 url http books.google.com ?id qsP7mmhqvj4C&pg PA23&dq 22Jahn Teller distortion 22 ref The d sup 9 sup electronic configuration of this ion gives three electrons in the two degenerate crystal field theory e sub g sub orbitals, leading to a doubly degenerate ... more details
chembox Verifiedfields changed verifiedrevid 464388479 Name Selenic acid ImageFile Ref chemboximage correct ?? ImageFileL1 Selenic acid 2D.png ImageSizeL1 121px ImageNameL1 Structural formula of selenic acid ImageFileR1 Selenic acid 3D vdW.png ImageSizeR1 121px ImageNameR1 Space filling model of selenic acid IUPACName Selenic VI acid OtherNames Selenic acid Section1 Chembox Identifiers ChEBI Ref ebicite correct EBI ChEBI 18170 SMILES O Se O O O PubChem 1089 KEGG Ref keggcite correct kegg KEGG C05697 InChI 1 H2O4Se c1 5 2,3 4 h H2,1,2,3,4 InChIKey QYHFIVBSNOWOCQ UHFFFAOYAI StdInChI Ref stdinchicite correct chemspider StdInChI 1S H2O4Se c1 5 2,3 4 h H2,1,2,3,4 StdInChIKey Ref stdinchicite correct chemspider StdInChIKey QYHFIVBSNOWOCQ UHFFFAOYSA N CASNo Ref cascite changed ?? CASNo 7783 08 6 ChemSpiderID Ref chemspidercite correct chemspider ChemSpiderID 1058 RTECS VS6575000 Section2 Chembox Properties Formula chem H 2 SeO 4 MolarMass 144.9734 g mol Appearance Colorless deliquescent crystals Density 2.95 g cm sup 3 sup , solid Solubility 130 g 100 mL 30 C MeltingPt 58 C 331 K BoilingPt 260 C 533 K decomposes pKa similar to chem H 2 SO 4 RefractIndex 1.5174 D line, 20 C Section3 Chembox Structure MolShape tetrahedral at Se CrystalStruct Dipole Section7 Chembox Hazards ExternalMSDS MainHazards Corrosive, highly toxic NFPA H 3 NFPA R 2 Other OX NFPA F 0 RPhrases 23 25 33 50 53 SPhrases 20 21 28 45 60 61 Section8 Chembox Related OtherAnions selenious acid br hydroselenic acid br hydrogen selenide OtherCations sodium selenate OtherCpds Sulfuric acid br Selenium dioxide br Selenium trioxide br Telluric acid Selenic acid is the chemical compound with the chemical formula formula chem H 2 SeO 4 . It is an oxoacid of selenium , and its structure is more accurately described as chem HO 2 SeO 2 . As predicted by VSEPR theory , the selenium center is tetrahedral, with a Se O bond length of 161 picometre pm . ref name yost In the solid state, it crystallizes in an orthorhombic ... more details
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