Topic 2 - Bonding, Structure And Properties Of Matter

Question 1

What are the three types of chemical bond?

Answer 1

Ionic
Covalent
Metallic

Question 2

When does ionic bonding occur?

Answer 2

In compounds formed of oppositely charged ions of metals combined with non-metals

Question 3

When does covalent bonding occur?

Answer 3

Between atoms which share pairs of electrons. This happens in most non-metallic elements and in compounds of non-metals.

Question 4

When does metallic bonding occur?

Answer 4

Between atoms which share delocalised electrons and occurs in metallic elements and alloys

Question 5

What happens in ionic bonding?

Answer 5

A metal atom reacts with a non-metal atoms and electrons in the outer shell of the metal atom are transferred

Question 6

In ionic bonding what do the atoms become?

Answer 6

Metals become positively charged ions

Non-metals become negatively charged ions

Question 7

How do you represent ionic bonding?

Answer 7

Dot and cross diagrams

Question 8

What is an ionic compound?

Answer 8

A giant structure of ions held together by strong electrostatic forces of attraction in all directions in the lattice between oppositely charged ions

Question 9

How can ionic compounds be represented?

Answer 9

A ball and stick model or a 3D model

Question 10

What are the limitations of dot and cross diagrams for ionic bonding?

Answer 10

Don’t show structure of compound, size or arrangement

Question 11

What are the limitations of ball and stick diagrams for ionic bonding?

Answer 11

Doesn’t show size of ions

Presents gaps but there isn’t gaps in the bonds

Question 12

What are the limitations of 3-D models for ionic bonding?

Answer 12

Only shows outer layer of compound

Question 13

What are the properties of ionic compounds?

Answer 13

High melting and boiling points – strong bonds
When solid they can’t conduct electricity – ions held in place
When liquid ions are free to move and carry electric current
Dissolve easily – separate and free to move

Question 14

What is covalent bonding?

Answer 14

When atoms share pairs of electrons to form strong bonds

Question 15

How large are covalent bond is?

Answer 15

Consist of small molecules but some have very large molecules such as polymers

Question 16

Give examples of giant covalent structures.

Answer 16

Diamond and silicon dioxide

Question 17

How can covalent bonds and giant structures be represented?

Answer 17

Dot and cross diagrams
Displayed formulas
3D models

Question 18

What are the limitations of dot and cross diagrams for covalent bonding?

Answer 18

Don’t show size or arrangement

Question 19

What are the limitations of representing covalent bonding by the displayed formula?

Answer 19

Don’t show structure or which atoms the elements came from

Question 20

What are the limitations of using a 3-D model to represent covalent bonding?

Answer 20

Confusing

Don’t show where electrons have come from

Question 21

What are the properties of simple molecular substances?

Answer 21

Strong covalent bonds but weak forces of attraction
Very low melting and boiling points – easy to break intermolecular forces
Gases or liquids
Don’t conduct electricity – no free electrons

Question 22

What are polymers?

Answer 22

Small units linked together to form a long molecule that has repeating sections joined by covalent bonds

Question 23

How are polymers represented?

Answer 23

Displayed formula of the repeating unit in brackets to the number of repetitions

Question 24

What are the properties of polymers?

Answer 24

Large intermolecular forces so more energy is needed to break them
Solid
Low boiling points

Question 25

What are giant covalent structures??

Answer 25

All atoms are bonded to each other by strong covalent bonds

Question 26

What are the properties of a giant covalent structures?

Answer 26

Very high melting and boiling points | Don’t conduct electricity

Question 27

Describe diamond

Answer 27

Each carbon atom forms for covalent bonds with other carbon atoms

Question 28

What are the properties of diamond?

Answer 28

Very hard Doesn’t conduct electricity High melting point

Question 29

Describe graphite

Answer 29

Each carbon atom forms three covalent bond with three other carbon atoms forming layers of hexagonal rings which have no covalent bonds between layers One electron from each carbon atom is delocalised

Question 30

Describe Graphene

Answer 30

A single layer of graphite with a strong network of covalent bond

Question 31

What are the properties of graphene?

Answer 31

Strong Light Good electrical conductors - delocalised electrons

Question 32

Describe Fullerenes

Answer 32

Molecules of carbon atoms with hollow shapes.

Question 33

What are the properties of graphite?

Answer 33

High melting point – lots of energy needed to break covalent bonds Soft and slippery - no forces between layers Conducts electricity and thermal energy

Question 34

What is significant about the structure of fullerenes?

Answer 34

Based on hexagonal rings of carbon atoms but may also contain rings with five or seven carbon atoms

Question 35

What was the first fullerene to be discovered?

Answer 35

Buckminsterfullerene - forms hollow sphere

Question 36

How are fullerenes used?

Answer 36

Cage other molecules - deliver drugs to body Industrial catalysts - large surface area Lubricants

Question 37

What are carbon nanotubes?

Answer 37

Cylindrical fullerenes with high length to diameter ratios

Question 38

What are the properties of nanotubes?

Answer 38

Conduct electricity and thermal energy | Can be stretched without breaking

Question 39

What are nanotubes used for?

Answer 39

Electronics, nanotechnology and materials

Question 40

What is metallic bonding?

Answer 40

Sharing of delocalised electrons between metal atoms arranged in regular patterns

Question 41

What are the properties of metals?

Answer 41

Giant structures with strong metallic bonds | High melting and boiling points

Question 42

How are pure metals arranged?

Answer 42

Arranged in layers which allows them to be bent and shaped

Question 43

Why are alloys made?

Answer 43

Because pure metals are too soft for many users

Question 44

What are alloys?

Answer 44

A mixture of metals or a metal and another element to make them harder

Question 45

How are alloys harder than pure metals?

Answer 45

When another element is mixed with a pure metal the new metal atoms will distort the layers making it more difficult for them to slide over each other

Question 46

Describe a solid

Answer 46

Strong forces of attraction Fixed, regular arrangement Vibrate around fixed positions High density

Question 47

Describe a liquid

Answer 47

Weaker forces of attraction Particles close together but can move past each other Irregular arrangements More energy than solid - move at random directions slowly Less dense than solids

Question 48

Describe a gas

Answer 48

No forces of attraction between particles More energy than solids and liquids Free to move in random directions at high speeds Low density

Question 49

What does the amount of energy needed to change a state depend on?

Answer 49

The strength of the forces between the particles

Question 50

What are the limitations of the state models?

Answer 50

Doesn’t show forces All particles are represented as spheres Spheres are solid

Question 51

What does aq stand for?

Answer 51

Aqueous solutions

Question 52

How are nano particles used for medicine?

Answer 52

Tiny particles are absorbed more easily by the body Silver nanoparticles have antibacterial properties and used to make surgical masks and wound dressing Cosmetics - deodorant, moisturisers

Question 53

What are the effects of nano particles of health?

Answer 53

Not fully understood so tested thoroughly