Chapter 8 Flashcards
1
Q
What is Ionic Bonding?
A
Type of bonding where electrons are transferred from a metal ion to a non metal ion
2
Q
Ionic bonding is based on?
A
differences in electronegativity and
ionization energy
3
Q
What is Coulomb’s Law used for?
A
to calculate the amount of energy that is involved in the interaction between a pair of ions
4
Q
In coulomb’s law, a negative sign indicates?
A
an attractive force between the ions
5
Q
Columb’s law tells us that?
A
the ion pair has lower energy when bonded than individual ions.
6
Q
the closer the pair is when bonded, the more _____ the process is.
A
exothermic
7
Q
Columb’s law can also be used to calculate?
A
the repulsive forces between like charged atoms
8
Q
In case of diatomic molecules, we can use Columb’s law to?
A
find the exact spot where bond energy favors formation of a chemical bond
9
Q
What is Bond length?
A
the distance at which energy in the system is at a minimum
10
Q
All systems will bond in a way that?
A
maximizes the attractive forces and minimizes the repulsive forces between atoms/ions
11
Q
At short distances the repulsive forces _____? Why?
A
increase because of the closeness of the particles
12
Q
At large distances the repulsive forces _____? Why?
A
decrease because atoms are unable to bond
13
Q
What are Covalent Bonds?
A
bonds formed when non-metals share electrons
14
Q
In a covalent bond, electrons are?
A
shared equally or unequally
15
Q
if electrons are shared equally the bond is?
A
non-polar
16
Q
If electrons are shared unequally the bond is?
A
polar
17
Q
all polar covalent molecules will have?
A
partial charges
18
Q
Partial charges means?
A
there is a positive and negative pole
19
Q
What is electronegativity?
A
the ability of an atom to attract electrons to itself.
20
Q
The ability of an atom to attract electrons to itself, is based on?
A
nuclear strength
21
Q
Metals electronegativity values are _____.
A
low
22
Q
Non-metals electronegativity values are ________.
A
high
23
Q
Greater electronegativity difference between bonding elements leads to?
A
a less covalent bond, and more ionic bond
24
Q
Instead of the regents electronegativity values we use?
A
% ionic character
25
If a compound is able to
conduct an electric current when melted, its?
ionic
26
generally the % ionic character is?
greater than 50%
27
what are Dipolar molecules?
Molecules with a slight negative end,
and a slight positive end
28
why do Dipolar molecules have a slight negative end and a slight positive end?
a difference in electronegativity values between atoms
29
In an electric field, dipolar molecules will do what?
orient themselves
30
How are molecules with polar bonds but no dipole oriented?
oriented so charge differences are equally distributed over the entire molecule
31
In a molecule with polar bonds but no dipole, what happens to the charges?
the charge differences are cancelled out
32
In a molecule with polar bonds but no dipole, no one end of the molecule is?
greater in charge than the other
33
What types of molecules follow the rule associated with molecules with polar bonds but no dipole?
Linear, tetrahedral, and planar molecules
34
What is the rule associated with molecules with polar bonds but no dipole?
charge differences are equally distributed over the whole molecule
35
Group 1 always ______.
loses one electron
36
Group 2 always ______.
loses two electrons
37
Group 16 mostly _____.
gains 2 electrons
38
Group 17 mostly ______.
gains 1 electron.
39
Anions gain what?
electrons
40
What charge do anions have?
negative
41
How does an anions radius change?
It is larger than the atom before it
42
Cations lose what?
electrons
43
What charge does a cation have?
positive
44
How does a cations radius change?
It is smaller than the atom before it.
45
Why are cations significantly smaller?
they lose an entire energy level when bonding
46
What does the Isoelectronic Series involve?
Ions that have the same number of electrons when done with a reaction
47
All ions in the Isoelectronic series have?
the same noble gas configuration when bonded to another atom
48
What happens to the size across a isoelectronic series?
decreases
49
What happens to the nuclear charge across a isoelectronic series?
increases
50
As you go up the periodic table, electronegativity _______
increases
51
As you go across the periodic table, electronegativity______
increases
52
What is polarity?
An entity containing two distinct and opposite poles that can either attract or repel each other
53
As attractive forces in the system are maximized, what happens to the PE?
it decreases
54
when bonds are broken, the energy change is?
positive
55
when bonds are formed, the energy change is?
negative
56
breaking of bonds is _______.
endothermic
57
formation of bonds is __________.
exothermic
58
Strengths of the bond model (3)
1. Associates energy with the formation of bonds between elements
2. Shows relationships between atoms in a molecule
3. Visual tool to understanding chemical structure
59
Weaknesses of the bond model (2)
1. bonds are not physical structures
2. Can not explain some of the behavior we observe in molecules
60
Single bonds are the ______ bond
weakest
61
Double and triple bonds are the _______ bonds
strongest
62
Why are double and triple bonds so strong?
The bond lengths are shorter
63
3 assumptions of lone electron pairs
1. can be accurately drawn with Lewis dot diagram
2. structure we draw is accurate of the geometry of the model
3. We can illustrate the shape/ bending of a molecule
64
number of electron pairs around a Linear atom?
B:2 L:0
65
What are the 2 names of the electrons around a central atom?
Bonding and Lone
66
number of electron pairs around a Trigonal Planar atom?
B:3 L:0
67
number of electron pairs around a Trigonal Planar Bent or V shape atom?
B:2 L:1
68
number of electron pairs around a Tetrahedral atom?
B:4 L:0
69
number of electron pairs around a Trigonal Pyramidal atom?
B:3 L:1
70
number of electron pairs around a Bent or V shaped Tetrahedral atom?
B:2 L:2
71
number of electron pairs around a Trigonal Bipyramidal atom?
B:5 L:0
72
number of electron pairs around a Seesaw atom?
B:4 L:1
73
number of electron pairs around a T-shaped atom?
B:3 L:2
74
number of electron pairs around a Linear Trigonal bipyramid atom?
B:2 L:3
75
number of electron pairs around a Octahedral atom?
B:6 L:0
76
number of electron pairs around a square pyramidal atom?
B:5 L:1
77
number of electron pairs around a Square Planar atom?
B:4 L:2
78
Linear geometry has how many electrons
2
79
Trigonal planar has how many electrons
3
80
Tetrahedral has how many electrons
4
81
Trigonal bipyramidal has how many electrons
5
82
Octahedral has how many electrons
6
83
Bond angle of linear
180
84
Bond angle of Bent or V shaped Trigonal planar
slightly less than 120
85
Bond angle of Trigonal planar
120
86
Bond angle of tetrahedral
109.5
87
Bond angle of Trigonal pyramidal
107.5
88
Bond angle of Bent or V shaped tetrahedral
104.5
89
Bond angle of Trigonal Bipyramidal
120 in plane, 90 perpendicular to plane
90
Bond angle of Seesaw
Complex
91
Bond angle of T shaped
Approx. 90
92
Bond angle of Linear Trigonal bipyramid
180
93
Bond angle of Octahedral
90
94
Bond angle of Square Pyramidal
Approx. 90
95
Bond angle of Square Planar
90
96
Atoms that are linear
linear, Trigonal bipyramid
97
Atoms that are Trigonal planar
Bent or V-shaped, Trigonal Planar
98
Atoms that are tetrahedral
tetrahedral, trigonal pyramidal, Bent or V-shaped
99
Atoms that are Trigonal bipyramidal
Trigonal bipyramidal, Seesaw, T-shaped, Linear
100
Atoms that are Octahedral
Octahedral, Square Pyramidal, square planar
101
What are the diatomic molecules?
Hydrogen, Nitrogen, Fluorine, Oxygen, Iodine, Chlorine, and Bromide
102
duet rule
hydrogen, helium, lithium, beryllium, and boron form stable molecules when they share 2 electrons
103
Octet Rule
elements carbon and beyond form stable molecules when they are surrounded by 8 electrons
104
Exceptions to the octet rule
Boron Triflouride and Sulfur Hexafluoride
105
molecules with dipolar moment are ______
polar
106
molecules without a dipole moment are _______
nonpolar
107
Resonance
More than 1 valid structure exists for a molecule
108
Where is resonance usually found?
polyatomic ions
109
a bond will form if the energy in a system can?
lower its total energy
110
the simultaneous attraction of each electron by the protons generates a force that?
balances the proton- proton and electron- electron repulsive forces at the distance corresponding to bond length.
111
unequal sharing of electrons results in a ________ bond.
polar covalent
112
dipole moments
when a molecule has a center of positive charge and a center of negative charge
113
atoms in a stable compound have a _________ configuration.
noble gas
114
In Isoelectronic ions, what determines the size?
number of protons
115
For a series of isoelectronic ions, as size ____ the nuclear charge ________.
decreases, increases
116
lattice energy
change in energy that takes place when separated gaseous ions are packed together to form an ionic solid
117
lattice energy is also defined as?
the energy released when an ionic solid forms from ions
118
Ionic character ______ with EN difference
increases
119
bonds result from when?
A system is seeking its lowest possible energy
120
Localized Electron model
A molecule composed of atoms bound together by sharing electrons using atomic orbitals
121
electron pairs are assumed to be localized on a particular atom or?
in space between 2 atoms
122
Lone pairs
pair of electrons localized on the atom
123
bonding pairs
pair of electrons in the space between atoms
124
atoms want to achieve _______ configuration
noble gas
125
second row elements are assumed to always?
obey the octet rule
126
second row elements never?
exceed the octet rule
127
Which two elements often have fewer than 8 electrons around them in compounds?
Boron and Beryllium
128
When writing the Lewis structure for a molecule you do what first?
satisfy the octet rule
129
formal charge
difference in # of valence electrons and valance electrons assigned to the atom in the molecule
130
atoms in molecules try to achieve formal charges close to ?
zero
131
negative formal charges are expected to reside on?
the most electronegative atoms
132
Sigma bonds have what bonds?
single double and triple
133
Pi bonds have what bonds?
double and triple
