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Chemical Bonding (seneca) Flashcards

- types of bonds - ionic bonds - ionic compounds - covalent & metallic bonds - representing covalent bonds - states of matter - changing state - chemical properties - molecular forces & polymers -

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1
Q

What is ionic bonding?

A

Ionic bonding involves an attraction between oppositely charged ions.
Ionic bonds are found in compounds made of metals and non-metals.

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2
Q

What is covalent bonding?

A

Covalent bonding involves 2 atoms sharing 1 or more pairs of electrons.
Covalent bonds are found in most non-metal elements and in non-metal compounds.

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3
Q

What is metallic bonding?

A

Metallic bonding involves an attraction between positively charged ions and negatively charged delocalised electrons.
Metallic bonds are found in metals and alloys (mixtures of metals and other substances).

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4
Q

Positive ions are also called …

A

cations

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5
Q

The metals in Group - and - can easily lose electrons to become positively charged ions.

A

1 and 2

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6
Q

Negative ions are also called…

A

anions

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7
Q

The —— in Group - are most likely to gain electrons to fill up their electron shell and become negatively charged.

A

non-metals
7

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8
Q

Ions can be made up of (2)

A
  • 1 atom (e.g. F-).
  • Combinations of atoms with an overall charge (e.g. SO42-).
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9
Q

Calcium is in group 2 of the periodic table. What happens to a calcium atom when it becomes an ion?

A

Because calcium is a Group 2 metal, there are 2 electrons in its outer shell.
Calcium atoms remove these 2 electrons to achieve a full outer shell containing 8 electrons, and in doing so become Ca2+ ions.

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10
Q

Non-metal atoms ——– electrons resulting in the formation of ——-
ions.

A

always gain
negative

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11
Q

In ionic bonding, a 1. transfers electrons to a 2.

A

1.metal atom
2.non-metal atom

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12
Q

The —— number in the periodic table tells you the number of electrons in an atom’s outer electron shell.

A

group

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13
Q

Noble gases already have a —– outer shell. Noble gases are ——– and ——- form ionic bonds with other elements.

A

full
inert
don’t normally

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14
Q

what are ionic lattices?

A

ionic lattices are are giant structures that are held together by strong electrostatic forces between the positive and negative ions.

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15
Q

Ionic compounds form when 1 transfer their outer electrons to 2 at the same time. The resulting oppositely charged ions are held together in 3

A

1.millions of metal atoms
2.millions of non-metal atoms
3.ionic lattices.

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16
Q

the———- are called ionic bonds and they extend in——-

A

electrostatic forces
all directions

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17
Q

What type of structure are ionic lattices?

A

giant structures

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17
Q

What do we call the electrostatic forces that hold ionic lattices together?

A

ionic bonds

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18
Q

give an example of small covalent molecules

A

water

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18
Q

Covalent bonds are strong because …

A

the shared electrons are attracted to the nucleus of both atoms

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18
Q

give an example of large covalent molecules

A

polymers such as polyester and silk

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19
Q

give an example of giant covalent structures

A

diamond

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20
Q

Metallic bonds are the

A

electrostatic attractions between positive ions and negative delocalised electrons.

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21
Q

The metallic bond structure is a

A

regular lattice of positive ions (cations) in a ‘sea’ of delocalised electrons.

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22
Q

in metallic bonding, Metals are

A

giant structures of regularly arranged atoms

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23
Q

in metallic bonding, delocalised electrons are …

A

NOT bound to an atom and are free to move around within the lattice.

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24
Q

Delocalisation happens because

A

metal atoms have a small number of electrons in their outer shells.

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25
Q

The electrostatic attractions found within metals are between ————and ——–

A

positive metal ions
delocalised electrons.

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26
Q

Dot-and-cross diagrams can be used to represent

A

covalent bonds and to show the sharing of electron pairs.

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27
Q

Double and triple bonds are normally —– and require —- energy to break.

A

stronger
more

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28
Q

what are the three types of covalent bonds

A

single covalent bonds
double covalent bonds
triple covalent bonds

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29
Q

A limitation of the dot and cross with shells diagram is that

A

it shows electrons differently for each atom, when they are actually exactly the same.

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30
Q

A limitation of the ball and stick diagram is that …

A

atoms are much closer together than the diagram show

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31
Q

what are the different covalent bond diagrams

A

Dot-and-cross without shells
Dot-and-cross diagram with shells
Line diagram
Ball-and-stick diagram

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32
Q

Which type of bonding involves an attraction between positively charged ions and negatively charged delocalised electrons?

A

metallic bonding

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33
Q

Why do electrons become delocalised in metals?

A

Because the electron shells in metal atoms overlap.

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34
Q

A 1 reactive metal (one that forms positive ions more easily) can displace a 2 reactive metal from a compound.

A

1.more
2.less

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35
Q

what is a displacement reaction?

A

A more reactive metal (one that forms positive ions more easily) can displace a less reactive metal from a compound.

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36
Q

In solids, particles are…

A

very close together and vibrate in a fixed position.

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37
Q

Solids have a —– shape and volume.

A

fixed

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37
Q

When solids are heated, the particles …

A

vibrate more intensely

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38
Q

In liquids, particles are

A

very close together but they move and flow randomly past one another.

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39
Q

Liquids have a —– volume but…

A

fixed
can change shape and fill a container

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40
Q

When liquids are heated,

A

the average speed of particles increases.

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41
Q

In gases, particles are —— and move …

A

far apart
randomly in all directions.

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42
Q

Gases —– shape and volume to fill whatever container they are in.

A

change

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43
Q

When gases are heated,

A

the average speed of particles increases

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44
Q

what are The ‘Simple Sphere’ Model disadvantages

A

-Forces between particles aren’t shown.
-It’s impossible to know how strong these forces are and how much energy is needed to overcome them.
-Shows particles as spherical when they actually are not.
-Particle collisions aren’t as simple as the model suggests.
-Shows particles as solid when they actually are not.
-Particles don’t ‘bounce off’ each other like snooker balls, as this model suggests.

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45
Q

the amount of energy required for substances to change state depends on whether …

A

the forces between their particles are strong or weak

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46
Q

substances with strong forces have a — melting and boiling points

A

high

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47
Q

substances with weak forces have a — melting and boiling points

A

low

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48
Q

What do we call the letters that tell us the state of matter of substances in a chemical equation?

A

state symbols

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49
Q

What process converts particles from a solid to a gas?

A

sublimation

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50
Q

what is a giant ionic lattice

A

Structure formed by ionic compounds

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51
Q

To break ionic bonds,

A

significant energy is needed to overcome the electrostatic forces between the ions and electrons in the lattice.

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52
Q

Because of this, the melting and boiling points of ionic compounds is …

A

high

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53
Q

When solid, the ions in the lattice are fixed in place.This means that …

A

charges cannot flow, so electricity cannot be conducted.

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54
Q

When molten, or dissolved in water, the ions in the lattice can

A

move freely.

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55
Q

Small covalent molecules are held together by

A

strong intermolecular forces (forces within a molecule) called covalent bonds.

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56
Q

Intermolecular forces are….

A

forces between different molecules.

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57
Q

Lots of small covalent molecules can be held together by …

A

intermolecular forces.But these intermolecular forces are weak and easy to break.

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58
Q

intermolecular forces are weak and easy to break. This means small covalent molecules have —- melting and boiling points . They’re often —– or —— at room temperature.

A

low
liquids or gases

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59
Q

Small molecules have —— intermolecular forces.
This means that small molecules have —- melting and boiling points.

A

weak
low

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60
Q

Small molecules don’t contain ——— electrons.
Because of this, they ——- conduct electricity.

A

delocalised
cannot

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61
Q

Cl2 (the diatomic molecule of chlorine) is a small molecule with —–intermolecular forces between its molecules.
Chlorine is a —– at room temperature.

A

weak
gas

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62
Q

Bigger molecules —– other molecules with stronger intermolecular forces. This means that they have —— melting and boiling points than small molecules.

A

attract
higher

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63
Q

Bigger molecules don’t contain ——— electrons, and so —— conduct electricity.

A

delocalised
can’t

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64
Q

Sucrose is made of 45 atoms and has the formula C12H22O11.
Although sucrose is a simple molecule, its size means that its intermolecular forces are ———– for it to be —— at room temperature.

A

strong enough
solid

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65
Q

Graphite is a ————– that has a —— melting point than methane.

A

giant covalent structure
higher

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66
Q

Polymers are …

A

large, chain-like molecules that can extend for thousands of atoms.

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67
Q

Polymers are held together by:

A

-Strong covalent bonds between atoms in molecules.
-Weak intermolecular forces between molecules.

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68
Q

Because of the large size of polymer molecules, the…
This means that…

A
  • intermolecular forces add up to be quite strong.
  • polymers are usually solid when at room temperature.
69
Q

Many polymers melt easily because …

A

the intermolecular forces remain less strong than chemical bonds.

70
Q

Which of these is strongest?
covalent bonds
intermolecular forces in small molecules
intermolecular forces in large molecules

A

covalent bonds

71
Q

Polymers are made up of …
Because of this,

A

repeating units
we can show their chemical structure as a unit that is repeated lots of times.

72
Q

The ‘n’ in the bottom right of the polymer tells us …

A

how many times the unit is repeated to create the larger polymer molecule.

73
Q

The sum of intermolecular forces between smaller molecules is

A

small

74
Q

The sum of intermolecular forces between bigger molecules is —— than the sum of intermolecular forces between smaller molecules

A

greater

75
Q

Why are intermolecular forces stronger in polymers than small molecules?

A

polymers are bigger

76
Q

Giant covalent structures don’t have a specific formula because

A

the structure can be any size.

77
Q

in theory, giant covalent structures can continue —– - a diamond may have —————————— atoms.

A

forever
50,000 or 1,000,000,000 carbo

78
Q

High temperatures and significant energy are required to ——- the structure’s covalent bonds.

A

break

79
Q

Giant covalent structures exist as

A

1 large structure or molecule.

80
Q

There are no intermolecular forces in giant covalent structures because…

A

there is only 1 molecule.

81
Q

Pure metals have —- structures with strong electrostatic forces between …

A
  • giant
  • positive ions and delocalised electrons.
82
Q

Because the ions are arranged in—–, pure metals …

A

layers
easily move over each other when a force is applied.

83
Q

pure metals are —- and ——-

A

soft and malleable

84
Q

There are —— electrostatic forces between the positive metal ions and the negative delocalised electrons.

A

strong

85
Q

when there are strong electrostatic forces, there are — melting and boiling points.

A

high

86
Q

all ions in pure metal are the —– size

A

same

87
Q

An alloy is a combination of

A

2+ elements, where at least 1 is a metal.

88
Q

The ions of the different elements in alloys are —— sizes

A

different

89
Q

Because the ions are —— sizes in alloys,it makes it ….

A

different
harder for the layers to slide across each other when a force is applied to the alloy.

90
Q

alloys stronger than pure metals because,as it is

A

harder for the layers to slide across each other when a force is applied to the alloy.

91
Q

alloys are used in ———– because…

A

construction
they are harder and stronger

92
Q

Metals are good conductors of electricity because …

A

their delocalised electrons can carry a charge within the structure.

93
Q

The same delocalised electrons can also carry —- energy within the structure.

A

heat

94
Q

The electrons in metals move from the 1 to the 2.

A

1.negative terminal
2.positive terminal

95
Q

Properties of alloys (3)

A
  • Mixture of 2+ elements
  • Harder than pure metals
  • Layers are distorted
96
Q

Diamond ——- an electrical conductor because there are …

A

is NOT
no delocalised electrons in the diamond structure

96
Q

A —– energy is needed to break strong covalent bonds.

A

lot of

96
Q

Diamond has lots of ———– bonds. This means that diamond has a —- melting point.

A

strong covalent
high

97
Q

There are lots of strong covalent bonds in diamond. This makes it very soft/hard.(choose one)

A

very hard

98
Q

Because diamond is hard, it is used as a …

A

cutting tool to cut other materials.

99
Q

Every carbon atom in diamond is bonded to - other carbon atoms by …

A

4
strong covalent bonds.

100
Q

Graphite is an —— of carbon

A

allotrope (form)

101
Q

Every carbon atom in graphite is bonded to - other carbon atoms by ———.
This creates a …

A

3
strong covalent bonds
giant covalent structure.

102
Q

The carbon atoms form (graphite) layers of ——, with ——- keeping the layers together

A

hexagonal (6-sided) rings
weak intermolecular forces

103
Q

The layers can —– slide over one another, so graphite is very soft/hard

A

easily
soft

104
Q

graphite is useful as a …

A

lubricant and as pencil ‘lead’.

105
Q

Each carbon atom forms ? bonds.
This means that there is ! delocalised electron from …

A

?. 3
!.1
every carbon atom

106
Q

graphite is a — electrical conductor

A

good

107
Q

Each carbon atom has …

A

a delocalised electron

108
Q

Graphene is an ——- of carbon

A

allotrope (form)

109
Q

Graphene is a —— so it also conducts electricity because …

A

single layer of graphite
of the carbon atoms’ delocalised electrons.

110
Q

Graphene can/cannot conduct electricity

A

can

111
Q

Graphene has a thickness of…

A

just 1 atom (1 layer).

112
Q

graphene is almost a –dimensional structure, and so graphene is …

A

2
very light.

113
Q

in graphene, the —– covalent bonds between carbon atoms mean that it is also very …

A

strong
strong

114
Q

Graphene has lots of uses in …

A

electronics and composite materials (materials that have things added to make them more useful).

115
Q

Graphene makes materials stronger without making them …

A

much heavier.

116
Q

Graphene can be used in

A

solar panels, batteries

117
Q

a single layer of graphite is called …

A

graphene

118
Q

Fullerenes are …

A

molecules of carbon atoms that take up hollow structures.

119
Q

what are molecules of carbon atoms that take up hollow structures?

A

Fullerenes

120
Q

Fullerenes’ structure is usually carbon atoms arranged in ——, but …

A

hexagonal (6-sided) rings
pentagonal (5-sided) and heptagonal (7-sided) carbon rings can also be found

121
Q

—— was the first fullerene that was discovered

A

Buckminsterfullerene

122
Q

Generally speaking, —– fullerenes come in a wide range of size

A

spherical

123
Q

Generally speaking, spherical fullerenes come in a …

A

wide range of sizes

124
Q

fullerenes common uses include:
(3)

A

Catalysts.
Lubricants.
As vehicles for transporting drugs into our bodies

125
Q

Carbon nanotubes are …

A

fullerenes that take the shape of a cylinder.

126
Q

Carbon nanotubes are often called —– because …

A

molecular wires
they have a tiny diameter but can be incredibly long.

127
Q

Because of the —– covalent bonds between carbon atoms, nanotubes are…

A
  • strong
  • exceptionally strong for their size.
128
Q

The strength and electrical conductivity of nanotubes make them useful for:

A

In electronics.
In nanotechnology.
For strengthening materials (e.g. tennis racket frames).

129
Q

Spherical fullerenes are perfect for delivering drugs as they …

A

can trap molecules inside themselves.

130
Q

what the main 4 allotropes of carbon

A

fullerenes
diamond
graphite
graphene

131
Q

nanoparticles are _________nm long

A

1-100

132
Q

nanoparticles are __________ atoms long

A

10-1000

133
Q

Fine particles are _________ nm long

A

100-2500

134
Q

Fine particles are _________ atoms long

A

1000-25000

135
Q

coarse particles are ________nm long

A

2500-10000

136
Q

coarse particles are ________ atoms long

A

25000-100000

137
Q

name the three types of ‘clumps’ of particles

A

fine particles
nanoparticles
coarse particles

138
Q

what is another name for coarse particles

A

dust

139
Q

nanoparticles are —– than individual atoms but …

A

larger
too small to be seen with the human eye.

140
Q

The surface area to volume ratio of nanoparticles is

A

high.

141
Q

The surface area to volume ratio of nanoparticles is high.
This means that …

A

smaller amounts of materials can be used for our desired purpose (e.g. as catalysts or in sun cream) compared to using normal sized particles and still produce the same affect.This makes them cheaper and more efficient to use than larger particles.

142
Q

As nanoscience is still a very new area of research, there are still possible disadvantages of nanoparticles that

A

we do not know about.

143
Q

we don’t know the long-term effect of nanoparticles …

A

on the environment or on human health

144
Q

As particles get smaller, their surface area to volume ratio…

A

increases

145
Q

decreasing the length of a cube’s side by a factor of 100 —– its surface area to volume ratio by a factor of 100.

A

increases

146
Q

due to particles get smaller, their surface area to volume ratio increases, —- amounts of nanoparticles to be used for a desired purpose compared to using normal-sized particles.
This means that …

A
  • smaller
  • they are cheaper and more efficient to use.
147
Q

Using nanoparticles can also — the properties of the material completely.

A

change

148
Q

‘normal’ gold particles are extremely unreactive, but gold nanoparticles …

A

can be very efficient catalysts for many processes

149
Q

A normal-sized gold particle is unreactive. What could I do to use gold as a catalyst?

A

Decreasing the size of the particle to nanoparticle size transforms the gold particles into incredibly efficient catalysts due to a massive increase to their surface area to volume ratio

150
Q

The very high surface area of nanoparticles means that …

A

there is a larger surface on which reactions can be catalysed (sped up).

151
Q

Fullerene nanoparticles can be used to

A

efficiently deliver drugs to a specific area of the body to target a disease.

152
Q

Carbon nanotubes are used in new computer chips because …

A

of their good electrical conductivity.

153
Q

Nanoparticles are so small that …

Eg …

A
  • visible light passes through them, making them transparent.
  • white substances, like sun cream, can be made transparent by using nanoparticles.
154
Q

Nanoparticles can have a___________
p_______
These nanoparticles can be used to …

A
  • antimicrobial properties.
  • make deodorants more effective by killing bacteria that generate bad smells.
155
Q

state 5 uses of nanoparticles

A
  • electronics
  • cosmetics
  • deodorants
  • catalysts
  • medicine
156
Q

state the 3 types of bonding

A

ionic
covalent
metallic

157
Q

What is an ionic bond formed from?

A

an attraction between oppositely charged IONS

158
Q

What forces hold together an ionic lattice?

A

electrostatic forces

159
Q

What is the empirical formula of C7H4O2

A

C7H4O2

160
Q

what is a empirical formula?

A

The simplest whole number ratio of atoms of each element in a compound

161
Q

What type of bonding involves the movement of electrons from one atom to another?

A

ionic bonding

162
Q

Why are polymers often solid at room temperature but melt easily?

A
  • inter-molecular forces are still weaker than chemical bonds
  • their size means they have many inter-molecular interations
163
Q

what are Intermolecular forces?

A

forces that act between molecules

164
Q

Intermolecular forces are also called

A

inter-molecular interations

165
Q

simple covalent molecules are held together by —– intermolecular forces

A

weak

166
Q

what does delocalised electron mean

A

the electron is free to move throughout the structure and conduct
electricity and thermal energy.

167
Q

Graphite is formed of ——— atoms. These are not held together by
1 but rather by 2.

A

layers of carbon
1.covalent bonds
2.intermolecular forces

168
Q

the layers IN GRAPHITE can easily slide over each other making the compound …

A

slippery

169
Q

What is the charge on a carbonate ion?

A

2-

170
Q

Carbonate Ion is a …

A

NEGATIVE polyatomic ion with formula of CO3(2-)

171
Q

How many double bonds and single bonds are there in a carbonate ion?

A

number of single bonds =2
number of double bonds=1

172
Q

Graphite exists in a —– covalent structure.

A

giant

173
Q

Which feature of graphite’s structure makes it a good electrical conductor?

A

1 electron from every carbon atom is delocalised

science chemistry (18 decks)

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