CHEM 1A Lecture Notes - Lecture 15: Electronegativity
Document Summary
All molecules exclude volume, exerting steric forces. Other interactions depend more sensitively on electron distribution within molecules. Describes how molecules are like in condensed phases (water, proteins, other solids) Atoms cannot be put on top of each other bc their electron clouds repel. Magnetic tennis balls shows the range of interactions is greater. The bonds that form will be combos of s and p orbitals. Polar bc in c-n bonds, nitrogen is more electronegative and has more electron density. From afar, it just looks like a dipole (+-->) Allowed to adopt favorable orientations, (cid:2861)(cid:2863) or (cid:2862)(cid:2862), polar molecules attract each other w strength that weakens w distance as -1/r3. Curve is similar to the attraction between two ions. Xe has no dipole, on average, but measurements show: For a pair of xe atoms, these fluctuating dipoles are correlated. Last pair of xe atoms attract, e 1/r6. Highly polarizable molecules have large dipole fluctuations, and thus have stronger dispersion forces.
