predict molecular structure?
819123
You have to do this by analogy to other molecules.\nFor instance Se is in the same column as S and therefore SeO3 and SeO2 will look like SO3 and SO2.  Similarly SiF4 will have the structure of CF4. As comes two periods after N.\n\nFinally, the structure of simple molecules like SO2 can often be found on Wikipedia or here:\n http://www.3dchem.com/table.asp
1066004
You'll have to be more specific as to which chemicals you want to know about.  The building blocks of Genes are Organic Structures / chemicals as are the individual nucleic acids and nitrogenous bases.     \n\nPlease see my sources for more information.
488364
Chemexper.com its super cool , type in the name of the compound and it will give you a ton of info about the thing you are looking at. I order chemicals off of it but it was really useful in researching for my Ochem labs as well.
924472
well, it's hard to draw here. but when i want to find a chem structure, i look at http://www.chemfinder.com you can type naproxen sodium into the search box, and it draws out the structural formula and gives you the properties of the molecule. VERY COOL!
867434
Construct a Lewis structure for NH3 ( Use N as the central atom ):  first: Determine the total number of valence electrons in the molecule.  In this case there are 8.  Represent shared pairs of electrons between the bonded atoms.  There will be one line connecting each atom, with each line representing two electrons, accounding for six of the eight available electrons.  With the remaining two valence electrons, position them on the fourth unbonded side, satisfying the octet rule for Nitrogen.\n\nThe above described Lewis structure gives you the molecular structureTrigonal Pyramidal ( three bonding pairs and one non bonding pair)\n\nRules for predicting molecular shape by VSPER theory:\n\n1.  Determine Lewis structure\n2.  Determine the number of electron pairs (bonded and non bonded) surrounding a central atom.\n3.  Use VSEPR theory to decide what symmetrical three dimensional shape will accommodate all bonded and non bonded electron pairs.\n4.  Classify the shape of the molecule by considering the arrangement of the joined atoms only, ignoring the nonbonded electron pairs.  That is why, although the NH3 molecule  has four pairs of electrons around the central atom, ammonia's shape is trigonal pyramidal.
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One way is by growing a big, pure crystal of the material. Since all the molecules are the same, and the crystal is pure, then all the molecules must fit together a certain way to form the shape of the 'ideal' crystal. \n\nX-ray crystallography, which the previous answerer referred to, is when they shine a thin beam of x-rays through the crystal, to see how they are diffracted. This shows how the crystal is constructed inside.\n\nIn addition to this, if the molecules are large enough, an electron microscope can sometimes see the layers of molecules on the outside of a crystal, or the inner layers if it is split open. \n\nBy using techniques like this, scientist can build up a mental concept of what shape and size the basic units of the crystal must be, the molecules. Then they can make little stick-and-ball shapes that represent the molecules and build up large structures (representing very tiny crystals.) If their predictions are correct, the large shape they build up should resemble the actual crystals, with the same angles and the same shape planes, etc.\n\n19 NOV 06, 1756 hrs, GMT.
244911
The average spead of molecules or ASOM.
425506
Depending on the value of the fine-structure constant, it will change your answer.\n\nThe fine-structure constant has been cited as:\n\n7.297 352 568 x 10^-3\n\n1/137.035 999 11\n\n1/137\n\n1/136
1040448
ask your chem prof or tutor ..it's hard to explain over the internet!
241974
Just type the numbers in a search engine.  You probably will need to put them in quotes.\n\nAlso, http://chemfinder.cambridgesoft.com/
317042
www.chemfinder.com might help
178162
molecular memory and neuro net artificial intelligence.
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what you need to do, get a SI data book, and look up their natural state. not bonded with anything else, and possibly itself.\n\nPhophorus - white: molecular (P4). red: Chain. Black: Layer\nIodine - molecular (I2)\nMagnesium - hexagonal closest-packing\nNeon - cubic closest-packing\nArsenic -grey: 3d structure - Layer formation. yellow: molecular As4\nSulfur- molecular S8\nBoron - complicated structure.\nSelenium - grey: chain, Red: molecular: Se8\nGallium - Complicated\nCesium - body-centred cubic\nOxxygen - O2, O3 molecular
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go to\nwww.chemistry.com
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The position of the elements in the periodic table gives you clues about the valences of each element. Also, if you remember the formulae for familiar substances (like carbon dioxide, water, sulfur dioxide, hydrochloric acid, etc) that will also give you clues about possible or likely valences. \n\nThe final answer is:\n\nmemorize.
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u can use artificial inteligence in data mining the information on organic chemistry.\n\nAlso you can simulate, model and predict the chemical reactions using software based on artificial interlligence
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it is a method to calculate atomic and molecular structure from first principles. the basis is the Schrodinger wave equation. without use of a computer it is a hopeless task.