Module 2: Section 2- Electrons Bonding And Structure Flashcards
(138 cards)
1
Q
Electronic structure
What are electron shells made up of
A
Sub shells and orbitals
2
Q
Electronic structure
In current accepted model of the atom what energy do electrons have
A
Fixed energies
3
Q
Electronic structure
Where are electrons
A
Move around the nucleus in shells (energy levels)
4
Q
Electronic structure
What are all shells given
A
Numbers called principal quantum numbers
5
Q
Electronic structure
Which shells have highest energy
A
Shells furthest from nucleus
6
Q
Electronic structure
What are shells divided into
A
Sub shells
7
Q
Electronic structure
What are the type of sub shells
A
S p d and f (in order)
8
Q
Electronic structure
How may electrons can orbitals hold
A
2
9
Q
Electronic structure
How many orbitals in s subshell
A
1
10
Q
Electronic structure
Maximum electrons in s subshell
A
2
11
Q
Electronic structure
How many orbitals in p subshell
A
3
12
Q
Electronic structure
Maximum electrons in p subshell
A
6
13
Q
Electronic structure
How many orbitals in d subshell
A
5
14
Q
Electronic structure
Maximum electrons in d subshell
A
10
15
Q
Electronic structure
How many orbitals in f subshell
A
7
16
Q
Electronic structure
Maximum electrons in d subshell
A
10
17
Q
Electronic structure
How many orbitals in f subshell
A
18
Q
Electronic structure
Maximum electrons in f subshell
A
14
19
Q
Electronic structure
Subshells in 1st shell
A
1s
20
Q
Electronic structure
Total number of electrons in 1st shell
A
2
21
Q
Electronic structure
Subshells in 2nd shell
A
2s 2p
22
Q
Electronic structure
Total number of electrons in 2nd shell
A
8
23
Q
Electronic structure
Subshells in 3rd shell
A
3s 3p 3d
24
Q
Electronic structure
Total number of electrons in 3rd shell
A
18
25
Electronic structure
Subshells in 4th shell
4s 4p 4d 4f
26
Electronic structure
Total number of electrons in 4th shell
32
27
Electronic structure
What is an orbital
Region of space that an electron moves in
28
Electronic structure
Which orbitals have same energy
Orbital within the same sub shell
29
Electronic structure
What has to be true of electrons to be in same orbital
Have to spin in opposite directions
30
Electronic structure
What shape is an s orbital
Spherical
31
Electronic structure
What shape is a p orbital
Dumbbell
32
Electronic structure
What is and atom or ions electron configurations
Number of electrons and how they’re arranges
33
Electronic structure
How can electron configuration be shown
Subshell notation
Electrons in boxes
34
Electronic structure
Subshell notation
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 …
35
Electronic structure
What does each box represent in electronic configuration
Orbitals
36
Electronic structure
What does each arrow represent in ewlecxtronic configuration
An electron
37
Electronic structure
Why are the arrows opposite facing in electronic configuration
Show opposite spin
38
Electronic structure
Rules for filling shells
Fill lowest energy Subshells first
Fill orbitals with the same energy singly before they start sharing
Fills 4s subshell before 3d Subshells
39
Electronic structure
2 exceptions for 3d and 4s filling
Chromium and copper
40
Electronic structure
Nobles gas symbols in configuration
Used to shorten eg Calcium as [Ar] 4s2
41
Ionic bonding
Definition
Electrostatic force of attraction between two oppositely charged ions
42
Ionic bonding
When are ions formed
When electrons are transferred from one atom to another so as to have a full outer shell
43
Ionic bonding
What is electrostatic attraction
Holds positive and negative ions together which is very strong
44
Ionic bonding
When do you get an ionic compound
When oppositely charges ions form an ionic bond
45
Ionic bonding
What do dot and cross diagrams show
Arrangement of electrons in an atom or ion
46
Ionic bonding
What are giant ionic lattices
Structure is giants as each ion is electrostatically attracted in all directions to ions of opposite charge
47
Ionic bonding
Why do ionic compounds have high melting and boiling points
Strong electrostatic force of attraction which take lots of energy to overcome
48
Ionic bonding
Why do ionic compounds conduct electricity when they’re molten or dissolved
Ions in a liquid are mobile and came carry charge
49
Ionic bonding
Why do ionic computers not conduct electricity when solid
Ions fixed in position by strong ionic bonds so can’t carry charge
50
Ionic bonding
Why do ionic compounds tend to dissolve in water
Water molecules are polar(part of molecule has a small negative charge and other bits have small positive charge) water molecules are attracted to charge ions and pull them away from the lattice causing it to dissolve
51
Covalent bonding
What are molecules
When two or more atoms bond together covalently
52
Covalent bonding
What happens in coolant bonding
Electrons are shared so atoms have full outer shells
53
Covalent bonding
Definition
Strong electrostatic attraction between a shared pair of electrons and nuclei of bonded atoms
54
Covalent bonding
What do dot and cross diagrams show
How electrons behave in covalent bonds
55
Covalent bonding
Covalent exceptions
Some compounds have less than 8 electrons in the outer shell and some can use the d orbital to ‘expand the octet, meaning they have more than 8 electrons in the outer shell
56
Covalent bonding
Example of compound with less than 8 electrons in outer shell
BF3
57
Covalent bonding
Example of compound with more than 8 electrons in outer shell
SF6
58
Covalent bonding
What is average bond enthalpy
Measures energy required to break a covalent bond
59
Covalent bonding
What’s a double covalent bond
Two paired of shared electrons
60
Covalent bonding
What’s a triple covalent bond
Three pairs of shared electrons
61
Covalent bonding
What’s a dative bond
Both electrons come from one atom
62
Covalent bonding
Example of covalent molecule with a dative bond
Ammonium
NH4 ^+
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Covalent bonding
How’s dative covalent bond shown on diagram
Arrow pointing away from donor atom
64
Shapes of molecules
What does molecular shape depend on
Electron pairs around the central atom
65
Shapes of molecules
What are bonding pairs
Pair of electrons which are shared with another atom
66
Shapes of molecules
what are lone pairs
Pair of electrons which are not shared
67
Shapes of molecules
Why do electron pairs repel each other as much as they can
Electrons are all negatively charged
68
Shapes of molecules
What type of pair repels the most
Lone pairs repel more than bonding pairs
69
Shapes of molecules
What is the order of the strength of repulsion
Lp lp > bp lp > bp bp
70
Shapes of molecules
What is th bond angles in a molecule with 4 bp
109.5
71
Shapes of molecules
What is the bond angle in a molecule with 3bp and 1lp
All three bond angles are 107
72
Shapes of molecules
What is the bond angle in a molecule with 2bp and 2lp
The bond angle is 104.5
73
Shapes of molecules
What are the two types of flying wedges
Soldi triangle wedge
Broken lines wedge
74
Shapes of molecules
What does the solid triangle wedge mean
Bond coming out the page
75
Shapes of molecules
What does the broken lines wedge mean
Bond going into page
76
Shapes of molecules
How do you predict the shapes of molecules step by step
1. Find central atom
2. Work out number of electrons in the outer shell from periodic table and take into account charge
3. Add the number of bonded atoms
4. Divide number of electrons by 2 to find the number of electron pairs
5. Compare number of electron pairs with number of bonding pairs to find lone pairs
6. Corresponding to different pairs
77
Shapes of molecules
What is the name of the molecule with 2 bp and what is the bond angle
Linear
180’
78
Shapes of molecules
What is the name of the molecule with 3 bp and bond angle
Trigonal planar
120’
79
Shapes of molecules
What is the name of the molecule with 4 bp and what’s the bond angle
Tetrahedral
109.5’
80
Shapes of molecules
What is the name of the molecule with 3bp and 1lp
Trigonal pyramid
107’
81
Shapes of molecules
What is the name of the molecule of 2bp and 2lp and what’s the bond angle
Bent
104.5
82
Shapes of molecules
What is the name of the molecule with 5bp and what’s the bond angle
Trigonal bipyramidal
120’ 90’
83
Shapes of molecules
What is the name of the molecule with 6bp and he wants the bond angle
Octahedral
All 90’
84
Polarity and electronegativity
What’s electronegativity
Atoms ability to attract the electron pair in a covalent bond
85
Polarity and electronegativity
Electronegativity trend in periodic tab;e
Increases across periods and decreases down groups
86
Polarity and electronegativity
How is electronegativity measured
On the Pauling scale
87
Polarity and electronegativity
What makes a bond polar
In a covalent bond between atoms of different electronegativities the bonding electrons are pulled towards the more electronegative atom
88
Polarity and electronegativity
In a polar bond what dos the difference in electronegativity cause
A permanent dipole
89
Polarity and electronegativity
What is a dipole
Difference in charge between two atoms cased by a shift in electron density in the bond
90
Polarity and electronegativity
What makes a bond more polar
The greater the difference in electronegativity
91
Polarity and electronegativity
What is a non polar covalent bond
Atoms have equal electronegativity and so electrons are equally attracted to both nuclei
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Polarity and electronegativity
Examples of non polar bonds
Diatomic gases eg Cl2 and H2
93
Polarity and electronegativity
What determines whether or not the molecule will have an overall dipole
Arrangement of polar bonds in a molecule
94
Polarity and electronegativity
What happens if the polar bonds are arranged symmetrically so that the dipoles are opposite and equal
The molecule has no overall dipole and is non polar
95
Polarity and electronegativity
What is carbon dioxide an example of
A molecule which contains two polar bonds but no overall dipole
96
Polarity and electronegativity
When is there and overall dipole
If polar bond are arranged so that they don’t cancel each other out then charge is arranged unevenly across whole molecule and will have an overall dipole
97
Polarity and electronegativity
Example of polar molecule
Water is polar as the negative charge is positioned more towards the oxygen atom
98
Polarity and electronegativity
What’s re the notions for dipole
Delta + and delta - (delta- for more electronegative)
+———> (arrow towards more electronegative)
99
Polarity and electronegativity
What bond between elements are purely covalent and why
Bond between atoms of a single element because the electronegativity difference between the atoms is zero and so the bonding electrons are arranged completely evenly within the bond
100
Polarity and electronegativity
Transition between ionic to covalent bonding
Changes and most compounds between the two meaning often have covalent and ionic properties
101
Polarity and electronegativity
How can you use electronegativity to predict what type of bonding will occur between two atoms
Higher difference in electronegativity, more ionic in character the bonding becomes
102
Polarity and electronegativity
How can a molecule contain polar bonds but not be polar
If there are permanent dipoles but they are opposite and equal so they cancel out
103
Polarity and electronegativity and IMF
What are intermolecular forces
Attraction which holds molecules together
104
Polarity and electronegativity and IMF
Are IMF strong or weak
Much weaker than covalent ionic and metallic bonds
105
Polarity and electronegativity and IMF
What are the three type of IMF
Induced dipole-dipole or London forces
Permanent dipole-dipole interactions
Hydrogen bonding
106
Polarity and electronegativityand IMF
What is the strongest type of IMF
Hydrogen bonding
107
Polarity and electronegativity and IMF
what factors affect electronegativity
Nuclear charge
———————-
Atomic radius
Shielding
108
Polarity and electronegativity and IMF
Which element do electrons move towards
Element with highest electronegativity
109
Polarity and electronegativity and IMF
What type of IMF do all atoms and molecules have
London forces
110
Polarity and electronegativity and IMF
What causes an instantaneous dipole
Electrons in charge cloud are always moving really quickly and at any instant the electrons in an atom are likely to be more to one side
111
Polarity and electronegativity and IMF
What does an instantaneous dipole cause
An induced dipole in a neighbouring atom which causes the two dipole to be attracted to each other
112
Polarity and electronegativity and IMF
What happens in London forced because the electrons are constantly moving
Dipoles being created and destroyed but overall effect for atoms to be attracted to each other
113
Polarity and electronegativity and IMF
Are all London forced the same strength
No
114
Polarity and electronegativity and IMF
What causes a larger London force
Larger molecules with larger electron clouds
Molecules with greater surface areas as have bigger exposed electron cloud
115
Polarity and electronegativity and IMF
What needs to happen when you boil a liquid and link to London forces
Need to overcome IMF so that particles can escape to liquid surface so need more energy to overcome stronger IMFS so liquid worth stronger London forces will have higher boiling points
116
Polarity and electronegativity and IMF
What can London forces hold molecules in
A lattice
117
Polarity and electronegativity and IMF
How do London forced hold iodine together
Iodine atoms are held together in pairs bu strong covalent bonds to form I2 but the molecules are help together in a molecular lattice arrangement by weak induced dipole-dipole attractions
118
Polarity and electronegativity and IMF
What type of IMF do polar molecules form
Permanent dipole dipole
119
Polarity and electronegativity and IMF
What are permanent dipole dipole imfs
Delta negative and delta positive polar molecules cause weak electrostatic forces of attraction between molecules
120
Polarity and electronegativity and IMF
What is the strongest type of IMF
A hydrogen bond
121
Polarity and electronegativity and IMF
What is a hydrogen bond
Strong dipole dipole interaction between a hydrogen atom and a lone pair of electrons on a highly electronegative atom
122
Polarity and electronegativity and IMf
What are the highly electronegative atoms which form hydrogen bonds
NOF
Nitrogen
Oxygen
Fluorine
123
Polarity and electronegativity and IMF
Which are hydrogen bonded HF, HCl, N2O, H2O, NH3 and PH3
HF NH3 H2O
124
Polarity and electronegativity and IMF
What is see to show a hydrogen bond in a diagram and why
A dashed line to show the weakness of the iMF
125
Polarity and electronegativity and IMF
What has to be shown on a diagram of a hydrogen bond
Dipoles (delta + and - )
Lone pairs
Hydrogen bonds
126
Polarity and electronegativity and IMF
What is commonly lot marks for on a diagram with hydrogen bonds
Hydrogen has to come from between a lone pair of electrons
127
Polarity and electronegativity and IMF
What are the effects of hydrogen bonding on the properties of substances
Soluble in water and have higher boiling and freezing point than molecules of a similar size which are unable to form hydrogen bond
128
Polarity and electronegativity and IMF
Why do molecules with hydrogen bonds often have higher melting and boiling points
More energy’s required to overcome hydrogen bonds
129
Polarity and electronegativity and IMF
What are the anomalous properties of water
Ice is less dense than water
Relatively high melting and boiling points
130
Polarity and electronegativity and IMF
Reason for ice being less dense than water
Hydrogen bonds hold the molecule in an open lattice structure
131
Polarity and electronegativity and IMF
Reason for relatively high melting and boiling point of water
Hydrogen bonds are the strongest of the IMF so need more energy to overcome and desperate the molecules
132
Polarity and electronegativity and IMF
What is the main factor that determine the boiling point of a substance
Strength of the induced dipole dipole forces unless it can form hydrogen bonds
133
Polarity and electronegativity and IMF
Explanation for why the boiling points if the group 7 increase from HCl to HI
Although he permanent dipole dipole interactions are decreasing, the number of electrons in the molecule increases so the strength of the London forced increases
134
Polarity and electronegativity and IMF
What is true if two molecules have a similar number of electrons but one is more polar
Strength of the London forces will be similar but the more polar one will have stronger permanent dipole dipole interaction so a higher boiling point
135
Polarity and electronegativity and IMF
Explanation for simple covalent compound have low melting and boiling points
IMF that hold the molecules in the structure are weak so don’t need much energy to break so the melting points are normally low and often liquids or gases at room temperature
136
Polarity and electronegativity and IMF
Explanation for why polar molecules are soluble in water
What is a polar molecule so only tends a to dissolve other polar substances. Compounds won’t hydrogen bonds such as ammonia can form hydrogen bond with water molecules so will be soluble
137
Polarity and electronegativity and IMF
Are molecules that only have London forces soluble
No such as methane
138
Polarity and electronegativity and IMF
Explanation for why simple covalent compound don’t conduct electricity
Even though some have permanent dipoles, overall covalent molecules are uncharged which means they can’t conduct electricity
