Angles of Chemical Structures

[Sophia Hartwell 1F]

When drawing structures, are there any clues within the compound that could tell me which shape the structure should be?

[patienceokani]

The main clue that we can get to determine the molecular shape of a compound is how many atoms the central atom is bonded to as well as how many lone pairs there are on the central atom.

[amar_151]

I struggled with this at the beginning of lewis structures and molecular geometry as well. The best advice I can give that has helped me is to draw the atoms as far away from each other as possible. Remember electron electron repulsion!

[805812306]

I agree that this confusion has no clear cut rules to clarify which is the most stable shape of the structure. It is difficult to know which shape is the most likely especially when there are so many seemingly rule-breaking cases. The thing that has helped me the most has been practicing drawing different structures and looking at exceptions to the rules.

Also, remember to fill the octet!!!

[Ashley Tonthat 2B]

Hello,

I don't think the actual chemical formula will give any clues since the geometry is impacted by the number of atoms and lone pairs, but if you follow the octet/expanded octet rules (with few exceptions of Be and B) and memorize the VSEPR chart, it should help when visualizing the position of the atoms and electrons to tell what type of shape it is. Hope this helps.

[tashyavakil 2K]

we learned in class what the different structures are called. You can look at how many atoms are bonded and how many loan pairs there are and use a molecular structure chart to decipher what the molecule would be.

[Sophia Hartwell 1F]

Thank you guys! I found most of the replies to be very helpful.

[Caitlin_Chheda_1K]

Hi! I don't think you can immediately tell from looking at the compound name unless you have already practiced with that compound or compounds with the same valence electrons. The one thing I would recommend is drawing the Lewis structure in order to find out the electron and molecular geometry. Although drawing several of these can take time, it is the only way to know for sure.