Atomic and Molecular Structures

Question 1

What are resonance structures?

Answer 1

• the ideal formal charge on a neutral atom is = 0
• a lot of charge in one spot is unstable (lots of energy)
• therefore, spread out energy by spreading out the charge and lowering the energy (e- move freely) (partial charges)

Question 2

What is the most ideal structure of an atom?

Answer 2

a stable atom with a formal charge of 0
= valence e- - number of pi and sigma bonds attached - nonbonding e-
= valence e- - (sticks + dots)

Question 3

VSEPR shapes: linear

Answer 3

X - A - X
180 degrees
lone pairs: 0

Question 4

VSEPR: trigonal planar

Answer 4

A, X, X, X
120 degrees
lone pairs: 0

Question 5

VSEPR: tetrahedral

Answer 5

A, X, X, X, X,
109.5 deg
lone pairs: 0

Question 6

VSEPR: trigonal pyramid

Answer 6

A X, X, X,
107deg
lone pairs: 1

Question 7

VSEPR: bent

Answer 7

A X, X
104.5 deg
lone pairs: 2

Question 8

VSEPR: trigonal bipyramidal

Answer 8

A, X, X, X, X, X
180, 90, 120
lone pairs: 0

Question 9

VSEPR: octahedral

Answer 9

A X, X, X, X, X, X
180, 90
lone pairs: 0

Question 10

What is the strongest dipole-dipole intermolecular force?

Answer 10

Hydrogen bonding

Question 11

Define intermolecular force

Answer 11

electrostatic interactions between charges or partial charges on DIFFERENT molecules

Question 12

Heisenberg uncertainty principle

Answer 12

the momentum and position of the electron are impossible to determine with accuracy

Question 13

Pauli Exclusion principle

Answer 13

no two electrons can possess the same 4 quantum numbers

Question 14

Principal quantum number

Answer 14

n
- shell
larger n = higher energy and larger radius

Question 15

Azumithal quantum number

Answer 15

l (angular momentum)

• subshells/sublevels
• s p d f = 0 1 2 3

Question 16

Magnetic quantum number

Answer 16

ml

• orbital
• (-l to +l)
• orbitals i.e. px, py, pz

Question 17

Spin quantum number

Answer 17

ms

• +/-1/2
• same number = parallel (different orbitals)
• different number, same orbital (paired)

Question 18

Hund’s rule

Answer 18

e- in subshells will fill other orbitals first before filling same orbital twice

Question 19

Aufbau principle

Answer 19

e- will fill in lowest energy (n+l) first before higher energies

Question 20

Paramagnetic

Answer 20

• unpaired electrons present

- magnetic field aligns with spins of the electrons

Question 21

Diamagnetic

Answer 21

• no unpaired electrons

- repels magnetic field