Structure and Bonding

Question 1

Definition of a compound

Answer 1

Two or more elements which are chemically combined

Question 2

Definition of Covalent Bonding

Answer 2

Shared pair of electrons

Question 3

Definition of Ionic Bonding

Answer 3

(electrostatic) attraction between oppositely charged ions

Question 4

Describe the structure of NaCl

Answer 4

Giant ionic lattic (structure) electrostatic attraction Between Na⁺ and Cl^-

Question 5

Type of bonding in graphite

Answer 5

Covalent

Question 6

Describe the structure of diamond

Answer 6

Giant covalent structure where each carbon has 4 bonds

Question 7

Describe the structure of graphite

Answer 7

Giant covalent structure where each carbon has 3 bonds. It is arranged in layers.

Question 8

Definition of Metallic Bonding

Answer 8

(electrostatic) attraction between positive metal ions and the delocalised electrons

Question 9

Type of bonding in CO₂

Answer 9

Covalent

Question 10

Describe the structure of CO₂

Answer 10

Simple molecular

Question 11

Identify the bonding in H₂O and describe its structure

Answer 11

Covalent Simple molecular

Question 12

Identify the type of bonding in copper and describe its structure

Answer 12

Metallic Giant metallic lattice

Question 13

Identify the type of bonding in sodium and describe its structure

Answer 13

Ionic Giant ionic lattice

Question 14

Identify the type of bonding in Ca(OH)₂ and describe its structure

Answer 14

Ionic Giant ionic lattice

Question 15

Identify the type of bonding in SiO₂ and describe its structure

Answer 15

Covalent Giant covalent lattice/structure (giant molecular)

Question 16

Graphite, diamond, nanotubes and fullerenes are all _________________ of carbon

Answer 16

allotropes

Question 17

Explain why NaCl is a solid at room temperature

Answer 17

It has a giant ionic lattice It is held together by ionic bonds which are very strong Therefore it has a high melting point

Question 18

Explain why oxygen is a gas at room temperature

Answer 18

It has a simple molecular structure It is held together by weak intermolecular forces Therefore it has a low melting point

Question 19

Explain why iron is a solid at room temperature

Answer 19

It has a giant metallic structure It is held together by strong metallic bonds Therefore it has a high melting point

Question 20

Explain why iron conducts electricity as a solid and liquid

Answer 20

It has delocalised electrons which are free to move throughout the metal structure

Question 21

Explain why graphite conducts electricity

Answer 21

Each carbon has only 3 bonds. This leaves one delocalised electron Which is free to move throughout the structure

Question 22

Explain why diamond doesn’t conduct electricity

Answer 22

Each carbon has 4 bonds. It has no free electrons

Question 23

Explain why sodium chloride doesn’t conduct electricity as a solid

Answer 23

The ions can’t move and carry the charge

Question 24

Explain why sodium chloride conducts electricity when dissolved

Answer 24

The ions are free to move and carry the charge

Question 25

Explain why carbon dioxide doesn't conduct electricity

Answer 25

Its electrons aren't free to move and carry the charge

Question 26

Explain why molten magnesium chloride can conduct electricity

Answer 26

The ions are free to move and carry the charge

Question 27

Explain why methane is a gas at room temperature

Answer 27

It is a simple molecular substance It is held together by weak intermolecular forces Therefore it has a low melting point

Question 28

Explain why graphite has a very high melting point

Answer 28

It has a giant covalent structure which is held together by strong covalent bonds which require a lot of energy to break

Question 29

What property makes diamond useful for sharpening knives

Answer 29

It is very _hard_

Question 30

Explain why diamond is so hard

Answer 30

It is arranged in a giant lattice Each carbon has 4 bonds The lattice is rigid

Question 31

Explain why thermosetting polymers have high melting points

Answer 31

They have crosslinks between the chains made with covalent bonds which are strong

Question 32

What conditions can be changed to make high density polyethene instead of low density polyethene?

Answer 32

Temperature Pressure

Question 33

What is a nanoparticle

Answer 33

a particle between 1nm and 100nm in size

Question 34

Why do nanoparticles have different properties?

Answer 34

Because they have a much bigger surface area

Question 35

What are the risks of nanoparticles?

Answer 35

Their large surface area makes them very reactive/explosive (nano aluminium) Nanoparticles are easily absorbed by the lungs and there is little research into the long term health risks.

Question 36

Explain why copper is used to make wires rather than graphite

Answer 36

Copper and graphite both conduct electricity Copper and graphite both have a high melting point Graphite is soft and brittle Copper is strong and ductile

Question 38

Name properties you would expect of an ionic compound?

Answer 38

High melting point Doesn't conduct electricity when solid Conducts electricity when molten or in solution

Question 39

Name properties you'd expect of a simple covalent solid

Answer 39

Low melting point Brittle Dull Soft

Question 40

Name properties you'd expect of a metal

Answer 40

High melting point Conducts heat and electricity Hard Lustrous (shiny) Malleable (can be hammered into shape) Ductile ( can be drawn into wires)

Question 41

What is meant by the term diatomic?

Answer 41

molecule containing two atoms

Question 42

Name the diatomic elements

Answer 42

Hydrogen, nitrogen, oxygen, fluorine, chlorine, bromine, iodine (I Bring Clay For Our New House) (Have NO Fear Ice Cold Beer)