C2: Bonding

Question 1

What is an ion?

Answer 1

Electrically charges atom formed by a loss or gain of electrons

Question 2

What is an anion

Answer 2

Negative ion (Gaines electrons)

Question 3

What is a cation?

Answer 3

Positive ion (lost electrons)

Question 4

What hold ionic compounds together?

Answer 4

Strong electrostatic forces between opposite charged ions

Question 5

What is ionic bonding?

Answer 5

When non metals and metals react by transferring , they are held together by electrostatic forces between the opposite charged ions

Question 6

What is covalent bonding?

Answer 6

Non metal atoms share electrons

Question 7

What do metals form when they react, compared to non metals?

Answer 7

Mates lose electrons, non metals gain electrons

Question 8

What is the structure of ionic compounds?

Answer 8

Giant ionic lattice (forms crystals)

Question 9

Properties of a giant ionic lattice?

Answer 9

Regular arrangement of alternating negative and positive ions with strong electrostatic forces between opposite charges, acting in all directions

Question 10

Properties of ionic compounds and why they have this

Answer 10

Solid at room temp : strong electrostatic forces
Conductor of electricity ONLY when molten: the negative ions are free to move and carry charge
Usually soluble in water: water has a positive and negative end, so ionic ions attract and dissolve

Question 11

Dot and cross diagram for H2O, HCl, NH3, CH4, CO2

Question 12

Properties of covalently bonded molecules and why

Answer 12

Don’t conduct electricity- no free electrons
Gases or liquids - weak bonds (intermolecular)
Low melting points
Strong intramoléculaires forces

Question 14

What is an example of giant covalent structures?

Answer 14

Polymers (polyethene), graphite, diamond, silicon dioxide

Question 15

Advantages and disadvantages of dot and cross diagrams?

Answer 15

A: useful for indicating the transfer of electrons
Shows which atom the bonding electrons came from
D: doesn’t show 3D arrangements
Does sos the relative size of atoms

Question 16

Advantages and disadvantages of ball and stick model

Answer 16

A: shows 3D arrangements
Shows shape and size
D: doesn’t show moevement of electrons
Inaccurate gap sizes between atoms

Question 17

Advantages and disadvantages of 2D diagrams of molecules

Answer 17

A: simple
Shows the atoms and how they are connected
D: can’t see the size and type of bond

Question 18

Describe a metallic structure

Answer 18

Giant structure of positive ions arranged regularly, electrons of the outer shell ( valence electrons) and they form a sea of delocalised electrons

Question 19

Properties of metallic ally bonded compounds and why

Answer 19

Conductors of electricity - delocalised electrons in the structure free to move through and carry charge
High m.p and strong: strong electrostatic forces Conductor
Malleable- layers which can slide

Question 20

What is an allotrope?

Answer 20

Different arrangements of atoms of the same element

Question 21

Allotropes of carbon?

Answer 21

Diamond, graphite

Question 22

Describe the structure of diamond

Answer 22

Tetrahedron structure, strong intermolecular forces, each carbon atom formed 4 strong covalent bonds

Question 23

Properties of diamond and why

Answer 23

Not conductor of electricity- no delocalised electrons Gases
High m.p- giant covalent structure with string intermolecular forces
Hard and dense- strong covalent bonds, each carbon atom forms 4 bonds, makes is useful in drill tips

Question 24

Describe the structure of graphite

Answer 24

Layers of hexagons, weak intermolecular forces between layers, each carbon atom forms three covalent bonds, conductor

Question 25

Properties of graphite and why

Answer 25

Conductor of electricity - one free electrons Gases per carbon atom, so it becomes delocalised in between the layers High m.p- giant covalent structure, strong covalent bonds Slippery- layers can slide and have weak intermolecular forces between them Graphite can be used to make inert electrodes for electrolysis

Question 26

What is graphene made from?

Answer 26

Carbon atoms, each one is covalent key bonded to 3 other (a single layer of graphite)

Question 27

How big is graphene?

Answer 27

One carbon atom thick

Question 28

Properties of graphene and why

Answer 28

Conductor- each carbon atom has one free electron which becomes delocalised Strong and high m.p- intramolecular covalent bonds are strong Transparent

Question 29

Uses of graphene

Answer 29

Electronics like touchscreens, composite materials

Question 30

What is fullerene made of?

Answer 30

A sphere of 60 carbon atoms

Question 31

How big is a fullerene (buckminster ball)

Answer 31

1nm diameter

Question 32

Properties of fullerenes

Answer 32

Slippery, low m.p

Question 33

Uses of fullerenes

Answer 33

Drug delivery in the body, catalyst (surface area to volume ratio, lubricants

Question 34

What is a nanotube made of?

Answer 34

Graphene rolled into a cylinder

Question 35

How big is a nanotube?

Answer 35

A few nm wide and several mm long

Question 36

Properties of nanotubes

Answer 36

Hugh tensile strength and resistant to breaking, conductors, high m.p

Question 37

Uses of nano tubes

Answer 37

Electronic, tennis rackets

Question 38

Uses of nanoparticles

Answer 38

Catalysts (high volume to surface area ratio) Gives flexibility to surgical masks and medical clothing, deodorant, suncream, white pigment in paint

Question 39

Advantages and disadvantages of nanoparticles

Answer 39

A: advanced technology without overuse D: unknown risks, could breathe them in and pass into cells