C3 Structure and bonding

Question 1

The ionic bonds between the charged particles result in an arrangement of ions called what?

Answer 1

a giant structure or giant lattice

Question 2

What is between the oppositely charged ions in giant structures of ions arranged in a lattice?

Answer 2

attractive electrostatic forces that act in ALL directions and are very strong

Question 3

What does the attractive electrostatic forces do?

Answer 3

holds the ions in the lattice together very tightly

Question 4

It takes a lot of what to break up a giant ionic lattice and why?

Answer 4

Energy- lots of strong ionic bonds to break

Question 5

How do we separate ions?

Answer 5

have to overcome all those electrostatic forces of attraction acting in all directions

Question 6

Hard to separate means ionic compounds have..

Answer 6

high boiling+melting points

Question 7

What happens to the ions once enough energy is supplied to separate the ions from the lattice

Answer 7

They become mobile and start to move around (solid to liquid)

Question 8

Ions are ___ to ___ anywhere in the liquid

Answer 8

free

move

Question 9

Why can’t a solid ionic compound conduct electricity?

Answer 9

ions are held in fixed positions in the lattice; ions cannot move around
They vibrate on the spot

Question 10

Many but not all ionic compounds will dissolve in water. When an ionic compound is dissolved in water, what happens?

Answer 10

lattice is split up by the water molecules. -> ions free to move around within the solution formed

Question 11

What is molten?

Answer 11

liquefied by heat.

Question 12

What is covalent bonding

Answer 12

When non-metals react together, their atoms share pairs of electrons to form molecules

Question 13

The atoms of non-metals generally tend to gain what?

Answer 13

gain electrons to achieve stable electron structures

Question 14

When non-metals react together, neither atom can give away electrons. So where do they get their electronic structure?

Answer 14

They get their electronic structure of a noble gas by sharing electrons

Question 15

In covalent bonding, the atoms in the molecules are then helped by what?

Answer 15

Shared pairs of electrons

Question 16

The strong bond between the shared pairs of electrons are called?

Answer 16

covalent bonds

Question 17

Many substances containing covalent bonds consist of what?

Answer 17

small molecules e.g. h20

Question 18

Some covalently bonded substances are very different to those small molecules. What do they have?

Answer 18

giant structures - where huge numbers of atoms are held together by a network of covalent bonds

Question 19

what are these covalent bonds in giant structures sometimes referred as?

Answer 19

macromolecules

Question 20

Diamond has what sort of structure?

Answer 20

giant covalent structure

Question 21

In diamond. how many covalent bonds does the carbon atom form?

Answer 21

4 covalent bonds w its neighbours

Question 22

Since the carbon has 4 covalent bonds, what does this result in?

Answer 22

a rigid giant covalent lattice

Question 23

What are dot and cross diagrams for?

Answer 23

to show bonding in covalent compounds

Question 24

Electrons drawn in the ____ between the outer orbitals of two atoms are ____ between atoms in covalent bonding

Answer 24

overlap

shared

Question 25

What are dot and cross diagrams useful for?

Answer 25

showing which atoms the electrons in a covalent bond come from

Question 26

What is a drawback of dot and cross diagrams

Answer 26

Doesn't show relative SIZES of the atoms | or how the atoms are arranged in space

Question 27

Displayed formula is useful for?

Answer 27

shows how atoms are connected in LARGE molecules

Question 28

drawback of displayed formula?

Answer 28

does not show 3d structure of the molecule | or which atoms the electrons in the covalent bond have come from

Question 29

What does the 3D models show?

Answer 29

the atoms, the covalent bonds and their ARRANGEMENT in space

Question 30

drwback for 3d models?

Answer 30

confusing for large molecules where there are lots of atoms to include does not show where the electrons in the bonds have come from either

Question 31

The atoms within the molecules are held together by very ___ ______ bonds but the forces of _____ between these molecules are very ____

Answer 31

strong covalent attraction weak

Question 32

To melt or boil a simple molecular compound, do you need high or low boiling/melting point?

Answer 32

low- feeble intermolecular forces and not the covalent bonds, molecules are easily parted

Question 33

As molecules get bigger..

Answer 33

intermolecular forces increases - more energy needed

Question 34

Molecular compounds don't of what and why?

Answer 34

conduct electricity- AREN'T CHARGED- no free electrons

Question 35

What are some properties of a giant covalent structure that gives substances?

Answer 35

high mp and bp insoluble in water Apart from graphite, hard and does not conduct electricity

Question 36

In graphite, carbon are only bonded to what?

Answer 36

three other carbon atoms

Question 37

What does the carbons form in graphite

Answer 37

hexagons, arranged in giant layers

Question 38

In graphite, there are no _____ bonds between the layers only weak ______ forces, so the layers can _____ over each other quite easily

Answer 38

covalent intermolecular slide

Question 39

Graphite is a ___ material that feels ______ to the touch

Answer 39

soft | slippery

Question 40

As the carbon atoms in graphite's layers are arranged in hexagons, each carbon forms what?

Answer 40

three strong covalent bonds

Question 41

Carbon atoms have ___ electrons in their outer shell available for _____. This leaves one space outer ______ on each carbon in graphite

Answer 41

four bonding one electron

Question 42

These mobile electrons can ____ freely along the ____ of carbon atoms. The mobile electrons found in graphite are called?

Answer 42

freely layers delocalised electrons

Question 43

Mobile electrons between the layers of graphite no longer what?

Answer 43

belong to any one particular carbon atom. They behave rather like the electrons in a metallic structure

Question 44

What do these delocalised electrons allow graphite to do?

Answer 44

conduct electricity- electrons will drift away from the negative terminal of a battery and towards its positive terminal when put into an electrical circuit

Question 45

Graphite is also an excellent conductor of what and why?

Answer 45

Thermal conductor | Energy is transferred to the delocalised electrons, rapidly transfer the energy along the LAYERS in the graphite

Question 46

Why can't diamond conduct electricity?

Answer 46

their atoms have no free electrons, as all their outer shell electrons are involved in a covalent bonding

Question 47

What are fullerenes

Answer 47

structures where carbon atoms join together to make hollow cages

Question 48

Cyndrical fullerenes called carbon nanotubes can also be produced, they form what?

Answer 48

incredibly thin cylinders, whose length is much greater than their diameter

Question 49

What useful properties do incredibly thin cylinders have?

Answer 49

high tensile strength | high electrical conductivity and high thermal conductivity

Question 50

The atoms in metals are built up as?

Answer 50

layer upon layer in a regular pattern

Question 51

Regular pattern in atoms of metals mean?

Answer 51

that metals form crystals

Question 52

What is metal another example of?

Answer 52

giant structures

Question 53

A metal has a lattice of...

Answer 53

positively charged ions

Question 54

How are the metal ions arranged?

Answer 54

regular layers, on top of another

Question 55

What can the outer electrons from each metal atom do?

Answer 55

easily move throughout the giant strucutre

Question 56

In metallic structures, the outer electrons form what?

Answer 56

a 'sea' of free-moving electrons surrounding the positively charged metal ions

Question 57

What bonds the metal ions to each other?

Answer 57

Strong electrostatic attraction between the negatively charged electrons and the positively charged ions

Question 58

The sea of delocalised electrons are no longer ____ with any particular ____ __ in the giant metallic structure

Answer 58

linked | metal ion

Question 59

What is an alloy

Answer 59

a mixture of two or more elements

Question 60

Describe why metals can be bent, shaped and pulled out into wires when forces are applied?

Answer 60

layer of atoms (positively charged ions) slide over each other easily

Question 61

What word can be used to describe a material that can be hammered into shape and drawn out into wire?

Answer 61

malleable | ductile

Question 62

Using knowledge of metal structures explain why alloying a metal can make the metal harder?

Answer 62

differently sized atoms inserted regular arrangement of metal atoms (positively charged ions) disrupted more difficult for laters to move

Question 63

Explain why metals are good conductors of thermal energy and electricity?

Answer 63

sea of delocalised electrons drifting through metal's giant structure. mobile delocalised electrons gain energy when heated

Question 64

Explain why aluminium has a higher melting point than sodium

Answer 64

each aluminium donates 3 electrons into 'sea' of mobile delocalised electrons. Forming Al 3+ ions Comparted to one electron in lattice of Na+ ions Electrostatic forces of attraction in metallic bonding stronger in aluminium because of a higher charge + more electrons involved in metallic bonding

Question 65

What is meant by nanoscience?

Answer 65

study of particles between 1 and 100 nm in size

Question 66

explain why the properties of nanoparticles of a material may differ from the properties of a bulk material

Answer 66

normal materials: most atoms, molecules or ions exist within body of material- not exposed at surface of material nanoparticles: proportion of particles at surface is massively increased for same mass of material so properties different

Question 67

Why might nanoparticles be different from those for the same materials in bulk

Answer 67

have a high surface area to volume ratio, with a high percentage of their atoms exposed in their surface

Question 68

Nanoparticles may result in smaller quantities of materials such as ____, needed for what?

Answer 68

catalysts | industrial uses

Question 69

Give two uses of silver nanoparticles

Answer 69

* antibactericide in fridges * sprays in operating theatres, * wound dressings * on clothes

Question 70

Give an adv of using nanoparticles as catalyst

Answer 70

large surface area to volume ratio

Question 71

Why are some people concerned about the use of nanoparticles as catalysts?

Answer 71

EXPLOSIONS caused by sparks | HEALTH PROBLEMS if breathed in if nanoparticles escape into air / environment

Question 72

Explain two uses of nanoparticles in cosmetic products for the skin

Answer 72

Sun-screens- block UV light | face-cream: deliver active ingredients deeper beneath surface of skin

Question 73

How can nanoparticles possibly help to fight cancers

Answer 73

delivers drugs to the tumour and is then absorbed, then absorbs energy from lasers to damage tumour by affecting its proteins