Electronic Structure Flashcards

1
Q

What is the number given to each shell called?

A

Principal quantum number

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What can be said about the energy and principal quantum number when a shell gets further away from the nucleus?

A

The higher it’s energy and the larger it’s principal quantum number is

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are shells divided into?

A

Sub-shells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the 4 types of sub-shell?

A

S
P
D
F

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is an orbital?

A

A region of a sub-shell that contains a maximum of 2 electrons with opposite spins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is spin?

A

A type of momentum possessed by an electron which can either be up or down

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How many electrons can s sub-shells hold?

A

2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How many electrons can p sub-shells hold?

A

6

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How many electrons can d sub-shells hold?

A

10

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How many electrons can f sub-shells hold?

A

14

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What can be said about the energy of orbitals in the same sub-shell?

A

They have the same energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is spin-pairing?

A

When there are 2 electrons in an orbital which spin in opposite directions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What shape are s-orbitals?

A

Spherical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What shape are p-orbitals?

A

Dumbbell shape

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the formula for the number of electrons a shell can hold?

A

2n^2 (n being shell number)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is electron configuration?

A

The number of electrons and how they’re arranged

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Why do 4s sub-shells fill first before 3d sub-shells?

A

4s sub-shells have a lower energy level

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What did Werner Heisenberg came up with?

A

The theory that you cannot know the speed of an electron or it’s exact position

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What was Heisenberg’s theory called?

A

Uncertainty principle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How do ions form?

A

When atoms lose or gain electrons to become positively or negatively charged

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is electrostatic attraction?

A

A strong force between positive and negative ions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is an ionic bond?

A

An electrostatic attraction between 2 oppositely charged ions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is an ionic compound?

A

When oppositely charged ions form an ionic bond

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are ionic crystals?

A

Giant lattice (regular structure) of ions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

How does a lattice form?

A

When each ion is electrostatically attracted in all directions to ions of the opposite charge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Describe the electrical conductivity of ionic compounds

A

Conduct electricity when molten or dissolved, but not when solid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Why do ionic compounds not conduct electricity when solid?

A

There are no mobile ions as they’re fixed in position by strong metallic bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Why do ionic compounds conduct electricity when molten or dissolved?

A

They have ions that are free to move (mobile ions) so can carry charge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Describe the melting and boiling points of ionic compounds?

A

Have high melting and boiling points

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Why do ionic compounds have high melting and boiling points?

A

The giant ionic lattices are held together by strong electrostatic forces (which takes lots of energy to overcome)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Describe the solubility of ionic compounds

A

Tend to dissolve in water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Why do ionic compounds tend to dissolve in water?

A

Water molecules are polar, so the water molecules pull the ions away from the lattice and cause it to dissolve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What does polar molecule mean?

A

Part of the molecule has a negative charge, the other bits have a positive charge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

How are molecules formed?

A

When 2 or more atoms bond together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What are molecules held together by?

A

Strong covalent bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What is a covalent bond?

A

The strong electrostatic attraction between a shared pair of electrons and the nuclei of the bonded atoms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Give an example of a molecule with triple bonds

A

Nitrogen (N2)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Give an example of a molecule with double bonds

A

Oxygen (O2)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What is different between a single covalent bond and a dative covalent bond?

A

In a single covalent bond, atoms share electrons with the electrons coming from each atom. Dative covalent bonds shares electrons but both electrons come from the same atom

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

How can you show a dative bond on a diagram?

A

By an arrow, pointing away from the donor atom

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What is different about boron trifluoride?

A

The boron only has 6 electrons on its outer shell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What does expanding the octet mean?

A

Having an outer shell with more than 8 electrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Give an example of a molecule that expands the octet

A

Sulfur Hexafluoride, has 12 electrons in it’s outer shell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What does enthalpy mean?

A

Another word for energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What does the average bond enthalpy tell you?

A

The strength of a covalent bond

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What does average bond enthalpy measure?

A

The average energy needed to break a bond

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What does the shape of a molecule depend on?

A

The number of pairs of electrons in the outer shell of the central atom

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

What are shared electrons called?

A

Bonding pairs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

What are unshared electrons called?

A

Lone pairs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

What do pairs of electrons do?

A

Repel each other (as they’re both negatively charged)

51
Q

Which repels more, lone pairs or bonding pairs?

A

Lone pairs

52
Q

Why do lone pairs repel more?

A

Being closer to the central atom causes lone-pairs to take up more of the available ‘bonding space’

53
Q

What is electron pair repulsion theory?

A

That the greatest bond angles are between lone pairs of electrons, and bond angles between bonding pairs are reduced because they’re pushed together by lone pair repulsion

54
Q

When drawing shapes of molecules, what does a broken line (e.g. |||||) show?

A

A bond pointing away from you

55
Q

When drawing shapes of molecules, what does a wedge line show?

A

A bond pointing towards you

56
Q

When drawing shapes of molecules, what does a line show?

A

A bond that isn’t pointing towards or away from you

57
Q

What is the bond angle of a linear shape?

A

180°

58
Q

What electron pairs does a linear shape have?

A

2 bonding pairs, 0 lone pairs

59
Q

Why do linear molecules have a bond angle of 180°?

A

The pairs of bonding electrons repel each other, so are positioned as far away as possible from each other

60
Q

What electron pairs does a trigonal planar have?

A

3 bonding pairs, 0 lone pairs

61
Q

What is the bond angle of a trigonal planar?

A

120°

62
Q

What electron pairs does a non-linear molecule (with 3 electron pairs) have?

A

2 bonding pairs, 1 lone pair

63
Q

What is the bond angle of a non-linear with 3 electron pairs?

A

A bit less than 120°

64
Q

What electron pairs does a tetrahedral have?

A

4 bonding pairs, 0 lone pairs

65
Q

What is the bond angle of a tetrahedral?

A

109.5°

66
Q

What electron pairs does a trigonal pyramidal have?

A

3 bonding pairs, 1 lone pair

67
Q

What is the bond angle of a trigonal pyramidal?

A

107°

68
Q

What electron pairs does a non-linear (with 4 electron pairs) have?

A

2 bonding pairs, 2 lone pairs

69
Q

What is the bond angle of a non-linear with 4 electron pairs?

A

104.5

70
Q

What is a molecule with 5 bonding pairs called?

A

Trigonal bipyramidal

71
Q

What are the bond angles in a trigonal bipyramidal?

A

90° and 120°

72
Q

Why do trigonal bipyramidal molecules have 2 bond angles?

A

Because 3 of the atoms will form a trigonal planar shape (120°) and the other 2 atoms will be at 90°

73
Q

What is a molecule with 6 bonding pairs called?

A

Octahedral

74
Q

What are all the bond angles in an octahedral?

A

90°

75
Q

What types of bonds can only be purely covalent?

A

Only bonds between atoms of a single element (e.g. diatonic gases)

76
Q

What is electronegativity?

A

The ability of an atom to attract the bonding electrons in a covalent bond

77
Q

What is the general trend in electronegativity?

A

Increases as you move towards Fluorine

78
Q

What is the trend of electronegativity down a group?

A

It decreases

79
Q

What is the trend of electronegativity across a period?

A

It increases

80
Q

What does a higher electronegativity number mean?

A

Means that element is better able to attract the bonding electrons

81
Q

What are the covalent bonds in diatonic gases?

A

Non-polar

82
Q

What does non-polar mean?

A

Where the atoms have equal electronegativities and so the electrons are equally attracted to both nuclei

83
Q

What is a polar bond?

A

A covalent bond where a difference in electronegativity has caused a shift in electron density in the bond

84
Q

In a covalent bond between 2 atoms with different electronegativities, where are the bonding electrons pulled to?

A

The most electronegative atom

85
Q

In a polar bond, what does the difference in electronegativity between the atoms cause?

A

A permanent dipole

86
Q

What is a dipole?

A

A difference in charge between the 2 atoms caused by a shift in electron density in the bond

87
Q

Between 2 atoms, the greater the difference in electronegativity…

A

… The more polar the bond

88
Q

What do polar molecules have?

A

An overall dipole

89
Q

What determines whether a polar molecule has an overall dipole?

A

The arrangement of polar bonds

90
Q

Why does CO2 have no overall dipole?

A

Because it is a linear molecule, the shape of the molecule is symmetrical. This causes the dipoles to cancel each other out, so it will be non-polar and have no overall dipole

91
Q

For a greater difference in electronegativity, what will the difference in type of bond be?

A

The less covalent and the more ionic it will be

92
Q

In general, what will the bonds be if the difference in electronegativity is less than 0.4?

A

Non-polar covalent bonds

93
Q

In general, what will the bonds be if the difference in electronegativity is between 0.4 and 2.0?

A

Polar covalent bonds

94
Q

In general, what will the bonds be if the difference in electronegativity is greater than 2.0?

A

Ionic

95
Q

What are intermolecular forces?

A

Forces between molecules

96
Q

How strong are intermolecular forces compared to covalent, ionic or metallic bonds?

A

Much weaker

97
Q

What are the 3 types of intermolecular bonding?

A

Permanent dipole-dipole interactions
Induced dipole-dipole interactions
Hydrogen bonding

98
Q

Which is the strongest of the 3 types of intermolecular bonding?

A

Hydrogen bonding

99
Q

What does induced dipole-dipole interactions cause?

A

All atoms and molecules to be attracted to each other

100
Q

What cause a temporary dipole?

A

When the electrons in an atom are to more side than the other (increasing the charge on that side)

101
Q

What does a temporary dipole cause?

A

Another temporary induced dipole in the opposite direction of a neighbouring atom (which causes them to attract)

102
Q

What trend in strength of induced dipole-dipole interactions occurs the larger the molecule?

A

Larger the molecule, the larger the electron clouds meaning stronger induced dipole-dipole interactions

103
Q

Why do molecules with a greater surface area have stronger induced dipole-dipole interactions?

A

The have more of the electron cloud exposed

104
Q

What can induced dipole-dipole interactions also be called?

A

London forces

105
Q

What are permanent dipole-dipole interactions?

A

Where the ẟ+ and the ẟ- charges on polar molecules cause weak electrostatic forces of attraction between molecules

106
Q

What is Hydrogen bonding?

A

A bond that only occurs when Hydrogen is covalently bonded to fluorine, nitrogen or oxygen

107
Q

What is charge density?

A

A measure of how much positive or negative charge there are in a certain volume

108
Q

What is the charge density of Hydrogen like?

A

Very high as it is small

109
Q

What do molecules with Hydrogen bonding normally contain?

A

-OH or -NH groups

110
Q

What are the properties of molecules with Hydrogen bonding?

A

Soluble in water

High melting and boiling points

111
Q

Why do water and ammonia have very high melting points compared to the other hydrides in their group?

A

Because more energy is needed to break the Hydrogen bonds

112
Q

Why do icebergs float on water?

A

Ice is less dense than water

113
Q

How are water molecules in ice held together?

A

By Hydrogen bonds

114
Q

Why is ice less dense than water?

A

Ice has Hydrogen bonds. Since Hydrogen bonds are long, the molecules in ice will be further apart than in liquid (making it less dense)

115
Q

When drawing Hydrogen bonds, where does the ẟ+ go?

A

Goes on the H atom

116
Q

When drawing Hydrogen bonds, where does the ẟ- go?

A

On the electronegative atom

117
Q

What are the bonds and forces like in simple covalent compounds?

A

Strong bonds within compounds, but weak forces between the molecules

118
Q

What is the electrical conductivity of simple covalent compounds?

A

They don’t conduct electricity (as they’re overall uncharged)

119
Q

What is the melting and boiling points of simple covalent compounds like?

A

Melting and boiling points are low, as the intermolecular forces that hold together the molecules are weak, so don’t need much energy to break

120
Q

When melting or boiling and simple covalent compounds, what bonds/forces do you have to break?

A

Have to break the intermolecular forces that hold together the molecules in a compound (But not the covalent bonds that hold the atoms together in a molecule)

121
Q

What is the trend in melting and boiling points as intermolecular forces get stronger?

A

Melting and boiling points increase

122
Q

What is the solubility of simple covalent compounds with Hydrogen bonds?

A

Compounds with Hydrogen bonds can form Hydrogen bonds with water molecules, so will be soluble

123
Q

What is the solubility of simple covalent compounds that are non-polar?

A

Insoluble

124
Q

What are the 2 factors, as you go down the Group 7 Hydrides, that affect the strength of the intermolecular forces?

A

The polarity of the molecules decrease, so the strength of the permanent dipole-dipole interactions decreases
The number of electrons in the molecule increases, so the strength of the permanent dipole-dipole interactions increase