Chapter 10 - Chemical Bonding

Question 1

Bonding Theories

Answer 1

models that predict how atoms bond together to form molecules

Question 2

Lewis Model

Answer 2

electrons are represented as dots and dot/lewis structures as molecules

Question 3

Valence Electrons

Answer 3

electrons in the outermost principal shell

-most important in bonding

Question 4

Lewis Structure/Dot Structure

Answer 4

symbol of element with surrounding dots to represent valence electrons

Question 5

Octet

Answer 5

8 dots/valence electrons

-stable

Question 6

Duet

Answer 6

2 dots/valence electrons

-for He, its a stable electron config

Question 7

Chemical Bond

Answer 7

• sharing/transfer of electrons
• if shared, then it is COVALENT
• if it is transferred, it is IONIC

Question 8

Octet Rule

Answer 8

in chem bonding, atoms transfer or share electrons to obtain outer shells w 8 electrons

-except H + He

Question 9

Bonding Pair

Answer 9

electrons that are shared bw 2 atoms

Question 10

Lone Pair

Answer 10

electrons that are NOT shared

Question 11

Double/Triple Bond

Answer 11

shorter/stronger than a single bond

Question 12

Terminal Atoms

Answer 12

at the ends

-H are always terminal

Question 13

Expanded Octets

Answer 13

can form for period 3 elements and beyond.
ex)SF6 - sulfur has 12 e- surrounding it instead of 8

PCl5 - P has 10 e- surrounding it

Question 14

Resonance Structure

Answer 14

set of 2 or more lewis structures that describe the polyatomic bonding of a species.
in nature, resonance hybrids are found which are intermediates of all the resonance structures.

Question 15

VSEPR THEORY

valence shell electron pair repulsion

Answer 15

based on the idea that electron groups (lone pair, single bond, multiple bonds) repel each other
-repulsion bw neg charges determines the geometry of the molecule

Question 16

Electron Geometry

Answer 16

the geometrical arrangement of the electron groups lone pairs, single bond, and multiple bonds

-even though molecular geometry does not include electrons/lone pairs in their model, the atoms are still placed bc the electron/lone pair still exerts its influence

Question 17

Molecular Geometry

Answer 17

geometrical arrangement of the atom

single and multiple bonds; does NOT take into consideration lone pairs

Question 18

Representing bonds on paper

Answer 18

1 Straight Line - bond in plane of paper
2 Hashed Lines - bond is projecting into paper
3 Wedge - bond is projecting out of paper

Question 19

Major Molecular Geometry Shapes (5)

Answer 19

1 Linear
2 Bent
3 Trigonal Planar
4 Trigonal Pyramidal
5 Tetrahedral

Question 20

Electronegativity

Answer 20

the ability of an element to attract electrons w/in a covalent bond

ex) O is more electronegative than H, which means that shared e-‘s are more likely to be found near O

Question 21

Dipole Moment

Answer 21

separation of charge within the bond due to uneven electron sharing

Question 22

Polar Covalent Bonds

Answer 22

covalent bonds that have a dipole moment

Question 23

Electronegativity Trend on Periodic Table

Answer 23

Left to Right -Increasing electronegativity

Top to Bottom - decreasing electroneg

Question 24

Pure Covalent Bond

nonpolar

Answer 24

if two elements have identical electronegativities, then they share electrons equally

• electronegativity difference = 0-0.4
• no dipole moment, nonpolar

Question 25

Ionic Bond

Answer 25

if the electronegativity is so different bw two elements, like metal + nonmetal, then e-‘s are completely transferred

• electronegativity difference = 2.0+
• bond is ionic

Question 26

Polar Covalent Bond

Answer 26

If there is an intermediate electronegativity different between 2 elements, like bw 2 nonmetals, the bond is polar covalent
-electronegativity difference = 0.4-2.0

Question 27

Polar Molecule

Answer 27

one w polar bonds that add together - not cancel each other - to form net dipole moment

• if diatomic molecules contain a polar bond, then they are POLAR
• molecules of different elements’ polarity depends on its shape

Question 28

Dipole Vector representation

Answer 28

-the arrows/vectors point towards the negative pole, and have a positive sign on towards the positive pole

• if arrows point in exactly opposing directions, then the dipole moment CANCELS
• if the arrows point towards the same direction, then it is a POLAR MOLECULE

Question 29

Polar Bond

Answer 29

a bond is polar if two bonding atoms have different electronegativities

Question 30

Polar Shapes

Answer 30

• trigonal pyramidal

- bent

Question 31

Nonpolar Shapes

Answer 31

• linear
• trigonal planar
• tetrahedral

Question 32

The octer rule states that chem compounds tend to form o that each atom has an octet of e-s in ___-

Answer 32

the highest occupied energy level

Question 33

When the octet rule is satisfied, the outermost ____ are filled.

Answer 33

s and p orbitals

Question 34

That the boiling point of water (H2O) is higher than the boiling point of hydrogen sulfide (H2S) is partially explained by

Answer 34

hydrogen bonding

Question 35

Electron Groups

Answer 35

1 single bond
2 double bond
3 triple bond
4 lone pair (aka nonbonding pairs)