Big Idea 2

Question 1

Chemical bonds

Answer 1

forces that hold atoms together in compounds

Question 2

Covalent bonding

Electronegativity difference:

Answer 2

occurs when two nonmetallic atoms share at least one pair of electrons

difference of 1.7 or less

Question 3

Polar Covalent bonds

Electronegativity difference:

Answer 3

covalent bonds in which the electron pair(s) are shared unequally by the two atoms due to differences in electronegativity greater than about 0.4 and less than 1.7

Question 4

Nonpolar Covalent bonds

Electronegativity difference:

Answer 4

bonds in which electron pair(s) are shared equally by the two atoms due to a very small or no difference in electronegativity between the bonded atoms

Question 5

Bond Length

Answer 5

average distance between the nuclei of the two bonded atoms

Question 6

Steps to Drawing Lewis Structures

Answer 6

1. Arrange the atom labels in a reasonable, symmetrical skeleton.
2. Calculate total number of valence electrons, N, needed in the molecule. (Each atom needs 8 valence electrons)
3. Calculate the number of available electrons, A, by adding the number of valence electrons for each atom.
4. Calculate the number of shared electrons, S, using S = N - A
5. Place the rest of the available electrons around the atoms in order to achieve an octet for each atom except hydrogen. (Lone pairs)
6. Assign formal charges to each atom in the molecule.

Question 7

What is the equation for Formal Charge?

Answer 7

Formal charge = number of valence electrons - number of bonds - number of unshared electrons

Question 8

What are the three types of chemical bonds?

Answer 8

Covalent, Ionic, and Metallic

Question 9

What is the difference between an ionic and covalent bond?

Answer 9

A covalent bond is between two nonmetals

An ionic bond is between a metal and a nonmetal

Question 10

What are the differences in electrons between nonpolar covalent, polar covalent, and ionic bonds?

Answer 10

Question 11

How do you calculate % Ionic Character?

Answer 11

Question 12

What are the exceptions for the octet rule?

Answer 12

Beryllium (Br) has 4 electrons in outer shell

Boron (B) has 6 electrons in outer shell

Question 13

What are the electronegativity differences and % ionic characterbetween nonpolar covalent, polar covalent, ionic bonds?

Answer 13

Question 14

What is Lattice Energy?

Answer 14

The charge in energy observed when a mole of solid ionic compound is formed from its gaseous ions

Question 15

What is the equation for Lattice Energy?

Answer 15

Question 16

How are covalent bonds formed?

Answer 16

Formed from sharing of electrons pairs between two atoms and electrons shared belong to both atoms

Question 18

How are electrons shared in polar covalent and nonpolar covalent bonds and what is their electronegativity difference?

Answer 18

Polar Covalent: electrons are shared unevenly and large difference in electronegativity

Nonpolar Covalent: electrons are shared evenly and very small difference in electronegativity

Question 19

What elements does the Duet Rule apply to?

Answer 19

Hydrogen (H) and Helium (He)

Question 20

What is the VESPR Model?

Answer 20

Valence | Shell | Electron | Pair | Repulsion

Repulsion between pairs of electrons around an atom to cause them to be as far apart as possible