L.4 Electronegativity & Hybridization

Question 1

What are Quantum Numbers and what do they describe?

Answer 1

Quantum numbers describe size, shape, orientation, and number of atomic orbitals that an element poses.

Question 2

What does the principal quantum number describe?

Answer 2

n = energy level (shell)

Indicates electrons distance from the nucleus

Question 3

What does the azimuthal number describe?

Answer 3

l = subshell

0 to n-1

s p d f

Question 4

What does the magnetic quantum number describe?

Answer 4

ml = orbital

-l to +l

shapes of those orbitals

x y z-axis

Question 5

What does the spin quantum number describe?

Answer 5

ms = spin of an electron

plus or minus 1/2

Question 6

Bonding Orbitals

Answer 6

Created by head-to-head or tail-to-tail overlap of atomic orbitals of the same sign and are energetically favored

Question 7

Antibonding Orbitals

Answer 7

Created by head-to-head or tail-to-tail overlap of atomic orbitals that have opposite signs

Question 8

What kind of bonds do

Single bonds, Double Bonds and Triple Bonds contain?

Answer 8

• Single bonds are Sigma bonds which contain two electrons
• Double bonds contain one sigma bond and one pi bond (sharing of electrons between two unhybridized p-orbitals that align side by side.
• Triple bonds contain one sigma bond and two pi bonds

Question 9

SP3 orbitals character

Answer 9

25% S Character

75% P Character

Tetrahedral geometry

109. 5 bond angles
     * carbons with all single bonds are sp3*

Question 10

SP2 hybridized orbital character

Answer 10

33% S Character

67% P Character

Trigonal planar geometry

120 bond angles

carbons with one double bond are sp2

Question 12

Resonance

Answer 12

Resonance describes the delocalization of electrons in molecules that have conjugated bonds

Question 13

Conjugation

Answer 13

Occurs when a single and multiple bonds alternate, creating a system of unhybridized p-orbitals down the backbone of the molecule through which pi electrons can delocalize

• Resonance increases the stability of a molecule
• various resonance form all contribute to the true electron density of the molecule: the more stable resonance form, the more it contributes.
• Resonance forms are favored if they lack formal charge, form full octets on electronegative atoms, or stabilize charges through induction and aromaticity