Bonding & Percent

Lattice Energy:

The size of the Lattice Energy is dependent on the size of the charge on the ions and the size of the ions. Bigger ions have lattice energies that are smaller.

There are 9 cal/g of fat and 4 cal/g of carbs.


Problem with a question:

Rank the
C—F, C—O, C—I, C—H
from highest energy to lowest energy.
Should say C-F, C-O, C-N, C-H

Bonding length:

triple bonds < double bonds < single bonds. The more bonds, the shorter the bond length. Resonance structures have bonds
somewhere between single and double bonds. The more bonding atoms sharing the 2 electrons, the weaker the bond and the longer the bond length.

Light Absorbency question:
To find the wavelength: c = wavelength/frequency
c is the speed of light (3,00 x 10^8 m/s)


Try this site:

Iron Hydride:

iron hydride.png

Below change the word "atom" to "molecule"

One problems uses the formula S = N - A
N is the total number of valence electrons needed by all atoms to achieve noble gas configurations (Be “Happy”).
A is the total number of electrons available from the valence shells of the individual atoms.
S is the total number of electrons shared in the molecule.

Coulomb Potential Energy

NA is the number of molecules
Z1 and Z2 are the charges of the ions
e is the charge of an electron in coulombs convert the charges to coulombs then square it.
epsilon (the funny looking E on the bottom of the formula) is 8.85419 x 10-12 J-1C2m-1
r is radius in meters.


Go to the desktop on the computers or your flash drive and watch these videos in the AP Chemistry folder.
AtomicTheory 8: Light
AtomicTheory 9: Light and the Atom
AtomicTheory 10: The Light Equations
Bonding5: Lewis Structures of Covalent Compounds
EM radiation
Nature of Matter
Atomic Spect of H
Bohr Model
7.1 This video is also in the AP Chem Folder on the desktop.

Bond Length & Energy

Intermolecular Potential Energy (Intermolecular Forces)

Coulomb's Law



cam33 Jan 25, 2011 8:45 am
This rotation is fairly easy, but don't get ahead of yourself. You’ll miss little details and get the problem wrong. Trust me I know from experience. If you pace yourself, check your work, and read the chapter, you should do just fine with this rotation. Make sure you know valence electrons are the number of electrons in the outer most shell of the atom. You should also be sure to learn the exceptions to the octet rule and the VSEPR theory. Cam

shl624 Nov 1, 2010 8:39 am
So you're a kid trying to figure out another one of Mrs. Duncan's rotations, huh? Well, let this be your small vacation because Bonding and Percent is much easier than expected. Valence Electrons-Don't let the millions of little dots fool you. Those are valence electrons. They're determined by what group on the Periodic Table they're in. Group 1 have one electron, Groups 2-12 have 2, Group 13 has 3 with each column following increasing by 1.
Polar, Non-polar, and Electronegativity-Polar and Non-Polar are the same thing as Polar Covalent and Non-Polar Covalent. To find them go to pg. 161 and use the electronegativity chart to find the difference in your 2 chemicals. Once found, go to pg. 176 and use the scale to find the type of bond the compound is. Remember that all ionic bonds are polar and that the higher on the electronegativity scale the difference is, the stronger the bond. When a compound is made up of 2 non-metals, it is a covalent compound, but if it a compound made of a metal and a non-metal, it is considered to be ionic.
Molecular Geometry-To find the molecular geometry of a structure, refer to the chart on pg 200. Don't let the structure being written in a straight line fool you. You must look to see if it has a double bond or not which could make it bent or angular.
Writing a Lewis Dot Notation-When a chemical compound is given with a - above the subscript, it means that an extra electron was added to the compound so don't forget to draw the extra dot. Remember that electrons can be shared to form double and triple bonds. An unshared electron pair is 2 electrons (dots) that are not shared(a dash) with another chemical.
I hope this helps because this is what helped me out the most. Don't stress and don't be afraid to ask Mrs. Duncan. She can help more than this can. -Sam Lovorn-

mec3539 Nov 1, 2010 8:34 am
Don't let Bonding and Percent fool you. It's really not as hard as it looks! When dealing with electronegativity difference, turn to page 161 in your text book and find the electronegativity of both elements and subtract them from each other. Next go to page 176 and determine from the chart whether it would be polar or nonpolar. Remember: All ionic bonds are polar. When drawing Lewis Structures, remember to double check the periodic table to be sure you are using the correct number of valence electrons. Remember: Group 1 has 1, group 2-12 have 2, 13 has 3 and so on. On the questions that ask which of the following contains only covalent bonding and no ionic bonding, Remember, when you are given two nonmetals it is a covalent bond. When you are given a nonmetal and a metal it is an ionic bond. When determining the molecular geometry of a molecule, turn to page 200 and study the chart to determine the answer.

aza242 November 28, 2012 9:08 a.m.
First thing you need to know about bonding and percent... DON'T FREAK OUT! It is not as hard as the videos make it. This is one of the things that we did in Chemistry 1. Print of a sheet that shows the electronegativty of all elements and everything on the VSPER. With that you'll be able to do more than half the packet.

amb6424 November 28th, 2012 9:33 am
Bonding and Percent: Yep, you've done this before. During the beginning of Chem I, Mrs. Duncan went over the lewis dot structure and taught you how to figure out the perecnt problems. But, you probably don't remember everything she said, which is why you have your book, notes, and videos. My advice is to watch the videos if you have no clue what you're doing, but otherwise look through chapters 5 and 6. 5 will have an important electronegativity chart (not all printed charts have the correct numbers; I learned that the hard way) and will help with one of the labs you may have to do. Chapter 6 is the big one though; it has everything from polar covalent bonds to ionic bonds to lewis dot structures-- which is pretty much the entire packet.
The small percentage of the packet that are percent problems is relatively easy. Just work your way through, and don't be afraid to ask questions! Most of the packet is also multiple choice, but don't let that fool you. This adds up to one thing--
The problems are all simple, but if you aren't right the first try, re-do the problem. All of those deducted points add to something big at the end.
Print out: VESPR chart and the electronegativity chart for quick use. --Anna B

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