Help with Lewis Structures......?
954162
1.  they are the outer most electrons \n2.  8 because that is a full orbital and a octet.. they want to get a noble gas notation\n3. Covalent shares electrons Ionic bonds donate electrons due to low electronegativity
1090457
a the number of outer electron that will bond with other atoms to fill thei valence shells
908225
Go to this site and it will show you structures of a whole bunch of molecules with Carbon and without, by formula and by name, kind of mess around with it for a while. http://www.chem.purdue.edu/gchelp/molecules/index.html
754819
no too sure since its been a while since iv done this, but its a simple enough molecule, C2Br4  2Br to each carbon and a double bond between the carbons, its a linear moleule, not sure about the electronegativity of the elements as my notes r all packed away but the Br atoms should sit slightly of veritcal from each other toward the outside of the molecule. and im sure that the two halves sit at 90 degrees to each other, not sure if u call it this but if u do then 2 Br attached to one carbon will sit along the x- axis of the molecule and the two Br attached to the other carbon will sit along the Z-axis, ask ur tutor or teacher if this is correct as im not 100% sure\n\ntetrahedral only applies to CBr4, thats because the 4 Br are comin off the same carbon, because there are 2 carbons it changes it all together\n   (ignore the full stops, needed them to position the atoms decently)\n\nBr&#92; ........ /Br\n.......C=C\nBr/ ........ &#92;Br\n\nThis is not perfect but imagine the top Br on the left aiming toward you at 45 degrees and the top one on the right aiming away at 45 degrees, hope this helps
446372
You proffered the example of XeF4.  Now the Lewis structure for XeF4 gives an expanded octet, viz: AX4E2, where A represents the central atom (Xe) in this example; X represents a shared pair of electrons; and E represents an unshared pair.  Thus for XeF4 we have 4 shared pairs and 2 unshared pairs, i.e. 6 pairs.  \n\nNow whatever the principal energy level(n), there is 1 s orbital; and for n=2 and higher, there are 3 p orbitals; and for n=3 and higher there are 5 d orbitals. For n=4 and higher there are 7 f orbitals.\n\nNow considering XeF4 hybridization, for the 6 pairs of electrons there will be 6 orbitals [each orbital holds a maximum of two electrons with opposite spin]. That means sp3d2 hybridization.  That is the one s orbital, the three p orbitals and two of the five d orbitals form six sp3d2 orbitals.  Of course, we are talking here about valence shell electrons.  How would these orbitals fill?  Well, electrons are added to orbitals such that electrons with the same spin are added until there are no more empty orbitals, then the orbitals with one electron fill (i.e. add a second electron) by acquiring an electron of opposite spin.\n\nThis gives XeF4 sp3d2 hybrid orbitals and an octahedron orientation. \n\nConsidering the Lewis structure for water, as another example, we obtain a AX2E2 form. Thus sp3 hydrid orbitals and a tetrahedron orientation. The 4 hybrid orbitals come from 1 s and 3 p atomic orbitals.
932025
You mean the Valence Shell Configuration?\n\nIt is easy to find this by simply looking at the Group # (these are the column numbers). \n\nElements in Group 1 all have 1 electron in their valence shell, Elements in group 2 have 2 and so on...\n'\nIf you mean how many shells there are then look at the Period #  this is the horizontal groups) the Period # corresponds with the number of electron shells.\n\nElements in Period 2 have 2 electron shells, elements in Period 3 have 3 and so on...
373250
C3H7NO2 \n\nwww.chemfinder.com is a useful resource.  \n\nI hope this helps :)
199063
Al has atomic no.13,\nits e.c will be 2,8,3\nin lewis dot structures we represent the valence shell electrons by dots.\nIn case of Al,the valence electrons are 3.so,Al with 3 dots around it is the answer.
426762
you know its ionic because Na is a metal while Cl isnt. a metal and nonmetal almost always from an ionic bond. to draw a lewis digram, determine how many valence electons are in each and draw the diagram.. its kinda hard to explain without actually drawing it.. consult a chem bk.
904652
CH3CH2C(CH3)3.\nI guess you forgot to type the C before the parenthesis. If you didn't forget, then none of the answers is correct (you would be missing a carbon atom).\n\nChem-man I would have contacted you in private about this but you do not give us the option to e-mail you. I have seen several of your answers prompting askers to verify your answer through echemistryhelp. I checked the website and it is not a free one; you post a question and pay for the answer. I'd say that this is a form of indirect advertisement  which is against the community guidelines. Please refrain from doing that or I will have to report you.
127454
If such a compound existed, it would be ionic. Calcium (IV) Chloride.\n\nBut it won't exist, particularly as an ionic compound. You're not going to be able to pull the p electrons from the calcium without a fight and chlorine isn't strong enough (or even fluorine, for that matter). Maybe you can achieve the species in the gas phase ... I don't know.\n\nIf it's covalent, what possible structure could it have? What do the bonding orbitals look like?
1187807
a phd student in chem looking for basic chem material on the web.\n\nright.\n\nstart here: http://www.carleton.ca/~rburk/chem1000\n\na textbook might also be useful.
1049588
I think that you are trying to find the net ionic equation. \nWhich in this case would be \nAg+ (aq) + Br- arrow AgBr (solid)\nif you are trying to find a single replacement reaction?\nthen you need to put Br- instead of NO3- and cancel out the NO3 - on the product side? \nTried my Best.
843792
Be very careful:\nFirst, look at the electronegativity differences, the presence of groups like OH- or cations (like Na+ of soap)\nThen, you must know molecular geometries, it is highly important:\nFor BF3 this is a  trigonal planar compound, all differences of electronegativity B<F are canceled due to the position of the F atoms (every 120º on the same plane). It is not polar.\n[SnCl3]- this is a trigonal pyramid compound.\nCl\n I\n:Sn-Cl\n I\nCl\nAS you can see, Sn has a lone pair of electrons, making Cl atoms accommodate in the base corners of an imaginary pyramid. Even if Cl cancel each others dipolar momentum on the sides, they all point ↓. This is a polar compound.
261496
Doing the Lewis dot structure for lead is a little hard here since I can not necessarily draw the structure on the screen, but here is how to do it.\n\nFirst, take out your periodic table and see where Pb, lead, is located.  Then, determine how many s and p electrons you have, do not count the center electrons is basically what you do, meaning it has 4 outer electrons.  Thus, draw 4 dots around Pb, and you have a Lewis dot structure.
574078
This might help :)\nhttp://www.chemicalforums.com/index.php?board=8;action=display;threadid=3263
54536
There is one line (bond) between the H and the Br.  It looks like this: \nH-Br\nThat's all. To make it a Lewis dot structure, you can put 7 dots around the Br to represent the valence electrons.  \nHBr is hydrobromic acid in aqueous solution.