Bonding

Question 1

Positive ions are also known as …

Answer 1

Cations

Question 2

Negative ions are also known as …

Answer 2

Anions

Question 3

Ionic bonding

Answer 3

When metals lose electrons to become positive and non-metals gain electrons to become negative and involves an attraction between oppositely charged ions

Question 4

What charge does a metal have after ionic bonding?

Answer 4

Positive (ion)

Question 5

What charge does a non metal have after ionic bonding?

Answer 5

Negative ( ion)

Question 6

Ionic lattice

Answer 6

Ions make an alternating structure where each ion is surrounded by ions by the opposite charge

Question 7

Ionic properties (4)

Answer 7

• crystalline
• high melting/boiling points
• conductivity
• brittle

Question 8

What is conductivity due to?

Answer 8

Charged particles

Question 9

What is high melting/ boiling points due to ?

Answer 9

Need a lot of energy to overcome the strong electrostatic attractions

Question 10

Covalent bonding

Answer 10

A chemical bond of sharing electrons between 2 non-metals

Question 11

Why do simple covalent molecules have low boiling/melting points ?

Answer 11

Have extremely weak intermolecular forces ( results to being gas or liquid at room temp) but strong covalent bonds

Question 12

Why do melting/boiling points increase with size?

Answer 12

The bigger the molecules, stronger the forces

Question 13

Why can’t simple covalent compounds conduct electricity?

Answer 13

No delocalised electrons within compounds

Question 14

Silicon dioxide (4)

Answer 14

• large n.o of covalent bonds
• high meting/boiling points
• hard crystalline structure
• don’t conduct electricity

Question 15

Polymers

Solid) (3

Answer 15

• intermolecular forces are strong (chains are large)
• don’t conduct electricity
• large molecules made of repeating units bonded together as long chains

Question 16

Diamond

form of carbon) (4

Answer 16

• giant covalent structure with all carbon joined by covalent bonds in a giant lattice
• each carbon atom is covalently bonded to 4 other carbon atoms
• high melting/boiling
• hard ( arranged in rigid structure)

Question 17

Graphite

form of carbon) (3

Answer 17

• giant covalent structure with all carbon joined by covalent bonds in a giant lattice
• soft (weak attraction between layers of atoms so layers aren’t bonded together causing the layers to slide over each other easily )
• conducts electricity ( contains delocalised electrons that move along layers and carry charge through graphite

Question 18

Graphene (3)

Answer 18

• single layer of graphite
• extremely strong ( giant covalent structure)
• thermal and electrical conducted ( due to delocalised electrons))

Question 19

Fullerenes

form of carbon) (4

Answer 19

• structure based in carbon atoms in hexagonal rings + hollow centre
• catalyst
• high melting/boiling points
• good conductivity

Question 20

Carbon nanotubes (3)

Answer 20

• cylindrical fullerenes
• high thermal and electrical conductivity
• high melting/ boiling point

Question 21

What do delocalised electrons do?

Answer 21

Free to move throughout the metallic structure and therefore carry electrical and thermal charge throughout compound

Question 22

Examples of metallic properties (4)

Answer 22

• high melting/ boiling points
• solid at room temp ( except mercury )
• malleable
• conduct electricity and heat

Question 23

What is an alloy?

Answer 23

Mixture of metals with a metal or another element

Question 24

Layers in alloys (3)

Answer 24

• atoms are in various sizes so layer are interrupted
• layers can’t slide over each other
• alloys are stronger, harder, less malleable, less ductile

Question 25

Fuels cells

Answer 25

Use electrochemical reaction between hydrogen and oxygen in to release electrical energy

Question 26

What catalyst is used for majority of fuel cells?

Answer 26

Platinum metal

Question 27

How are nanoparticles useful for fuel cells?

Answer 27

Nanoparticles decrease cost ( platinum is catalyst- less platinum is needed)

Question 28

What do the nanoparticles in deodorants | do?

Answer 28

Kill bacteria to prevent the build up of unpleasant odours

Question 29

What groups does ionic bonding effect?

Answer 29

Group 1,2,6,7

Question 30

Metallic bonding

Answer 30

Electrostatic forces of attractions between positive ions and negatively charged delocalised electrons

Question 31

What do particles lose or gain when changing state?

Answer 31

Energy

Question 32

What determines how much energy is needed to change state?

Answer 32

The strength of forces between particles

Question 33

What is the process that changes solid into gas?

Answer 33

Sublimation

Question 34

Why cant small molecules conduct electricity?

Answer 34

They don't have delocalised electrons

Question 35

Why cant small molecules conduct electricity?

Answer 35

They don't have delocalised electrons

Question 36

Properties of simple molecular substances (3)

Answer 36

Weak intermolecular forces Low boiling/melting points Don't conduct electricity

Question 37

Intramolecular forces

Answer 37

Forces within molecules

Question 38

Properties of large molecules (3)

Answer 38

Strong intermolecular forces High boiling/melting points Don't conduct electricity

Question 39

Ionic Bond

Answer 39

Type of electrostatic force of attraction where opposite charged ions are attracted towards to each other

Question 40

Properties of ionic compounds

Answer 40

High melting/boiling points - strong bonds between particles

Question 41

What is the cause of metallic bonding?

Answer 41

The electrostatic forces of attraction between the positive nuclei and negative electrons

Question 42

Simple molecular substances

Answer 42

Made up from molecules containing few atoms joined together by covalent bonds

Question 43

As molecules get bigger...

Answer 43

The intermolecular forces get stronger

Question 44

Why are metals good conducters of heat and electricity?

Answer 44

The delocalised electrons carry electric charge and thermal energy through the whole structure

Question 45

Why are metals malleable?

Answer 45

Layers of atoms can slide over each other

Question 46

Why are metals solid at room temperature? (3)

Answer 46

Electrostatic force between metals atoms and delocalised electrons are very strong so lots of energy are needed to break them. This gives them a high melting/boiling point

Question 47

What causes solids to have a fixed volume?

Answer 47

The forces of attractions between particles

Question 48

What are nanoparticles used for? (5)

Answer 48

``` Catalysts Medicine Deodorants Electronics Cosmetics ```

Question 49

What is so useful about nanoparticles?

Answer 49

They have large surface area to volume ratio

Question 50

How are nanoparticles used in catalysts?

Answer 50

Their huge surface are to volume ratio - less material needed to work as an effective catalyst

Question 51

How are nanoparticles used in medicine?

Answer 51

Tiny particles so it is absorbed more easily into the body and deliver drugs right to atoms

Question 52

How are nanoparticles used in electronics?

Answer 52

They can conduct electricity

Question 53

How are nanoparticles used in cosmetics?

Answer 53

So small that visible light passes through them, making them transparent

Question 54

5 allotropes of carbon

Answer 54

``` Diamond Graphite Grapheme Fullerenes Silicon dioxide ```

Question 55

Why are silver nanoparticles added to deodorants?

Answer 55

They have antibacterial properties

Question 56

What makes covalent bonds so strong?

Answer 56

The electrostatic forces of positively charge nuclei to the sharing electrons

Question 57

Nanoscience

Answer 57

Scientific research to find new uses of nanoparticles

Question 58

What are disadvantages of nanoparticles?

Answer 58

Long term effects aren't discovered yet | How they affect the body or human health isn't fully understood

Question 59

How are fullerenes useful to deliver drug to body?

Answer 59

They form the structure around an atom to trap it

Question 60

Why are fullerenes good catalysts

Answer 60

They have huge surface are to volume ratio

Question 61

What is the type of covalent bond depend on?

Answer 61

How many electron pairs are shared