Exam 1 - Module 3

Question 1

Types of chemical bonds

Answer 1

ionic, covalent, metallic

Question 2

Octet rule

Answer 2

Main group elements bond in such a way that each atom has eight electron

Question 3

Ionic bond: Ionization energies

Answer 3

Metals have low ionization energies and want to form cations (+)

Question 4

Ionic bond: Electron affinity

Answer 4

Nonmetals have negative (favorable) electron affinities and want form anions (-)

e.g. Na+ (1e-) wants to give its electron to Cl- (7e-) so they can fill valence shell.

Question 5

Covalent bond electrons are shared between ____

Answer 5

Atoms (no charges formed)

Question 6

Polar covalent

Answer 6

electrons not shared equally with the electron density residing towards the more electronegative atom (most bonds - nonmetal)

Question 7

Nonpolar covalent

Answer 7

Electrons are essentially shared equally between the atoms (no difference in electronegativity) C-C or C-H

Question 8

Exceptions to the octet rule

Answer 8

Hydrogen likes 2 electrons, Boron likes 6 electrons, Aluminum likes 6 electrons

Question 9

Expanded octets

Answer 9

Ten or twelve electrons are possible, only occurs in period 3 elements or higher, thanks to D-orbitals.

Question 10

Central atom for drawing molecular lewis structure is:

Answer 10

The one with lowest electronegativity. Flourine is most electronegative, and as you go left and down on periodic table they get less electronegative

Question 11

formal charge equation (given on test!)

Answer 11

VE - #LPE - 1/2BE

Question 12

VSEPR Theory

Answer 12

Valence Shell Electron Pair Repulsion
-based on idea that electron groups (lone pairs, single bonds multiple bonds, single electrons) repel one another to achieve maximum separation

Question 13

AXE nomenclature

Answer 13

A = central atom
X = Peripheral atom
E = lone pair electrons

Question 14

Electronic geometry

Answer 14

Total number of electron groups => Big picture

Question 15

Molecular geometry

Answer 15

LPE effect the true shape