1.2 Bonding 1.3 Structures

Question 1

How can you tell which substances contain ionic bonds?

Answer 1

Ionic bonds occur in metal compounds/between a metal and a non-metal.

Question 2

How is an ionic bond formed?

Answer 2

Electrons are transferred from the metal to the non-metal.

Question 3

What is the definition of an ionic bond?

Answer 3

The electrostatic attraction between oppositely charged ions.

Question 4

What structure do ionic compounds have?

Answer 4

Ionic lattice.

Question 5

State two physical properties of ionic compounds.

Answer 5

• High melting point
• Conduct electricity when molten.

Question 6

Why do ionic compounds have high melting and boiling points?

Answer 6

They have strong ionic bonds that require a lot of energy to break.

Question 7

Why do ionic compounds not conduct electricity when solid?

Answer 7

When solid, the ions are not free to move and carry charge.

Question 8

Why do ionic compounds only conduct electricity when molten?

Answer 8

When liquid, the ions are free to move and carry charge.

Question 9

What is the definition of a covalent bond?

Answer 9

A shared pair of electrons.

Question 10

What types of elements are present in substances which contain covalent bonds?

Answer 10

Non-metals.

Question 11

Name three substances which are simple covalent/molecular covalent.

Answer 11

• Chlorine
• Ammonia
• Water.

Question 12

Why do simple covalent substances have low melting and boiling points?

Answer 12

They have weak van der Waals’ forces between molecules which require little energy to break.

Question 13

Why are simple covalent substances poor conductors of electricity?

Answer 13

They do not contain delocalised electrons that can move and carry charge.

Question 14

What is the definition of allotropes?

Answer 14

Different forms of the same element in the same state.

Question 15

Name three allotropes of carbon.

Answer 15

• Diamond
• Graphite
• Graphene.

Question 16

What type of bonding is present in diamond, graphite, and graphene?

Answer 16

Covalent.

Question 17

What type of structure do diamond, graphite, and graphene contain?

Answer 17

Giant covalent.

Question 18

State the properties of diamond.

Answer 18

• High melting and boiling points
• Poor conductor of electricity
• Hard.

Question 19

State the properties of graphite.

Answer 19

• High melting and boiling points
• Good conductor of electricity
• Soft.

Question 20

State the properties of graphene.

Answer 20

• High melting and boiling points
• Good conductor of electricity
• Strong.

Question 21

Explain the properties of diamond.

Answer 21

High melting point as it has strong covalent bonds between atoms which require a lot of energy to break; does not conduct electricity as it does not have delocalised electrons that can move and carry charge; hard as it has strong covalent bonds between atoms which require a lot of energy to break.

Question 23

What are the properties of graphite?

Answer 23

High melting and boiling point; conducts electricity; soft due to weak forces between layers.

Question 24

What are the properties of graphene?

Answer 24

High melting and boiling point; conducts electricity; strong due to strong covalent bonds.

Question 25

State a use of diamond.

Answer 25

Cutting tools.

Question 26

State a use of graphite.

Answer 26

Lubricant in machinery, pencil leads.

Question 27

State a use of graphene.

Answer 27

Solar cells, batteries.

Question 28

What is the definition of a metallic bond?

Answer 28

The attraction between delocalised electrons and a regular lattice of positive ions.

Question 29

Draw a labelled diagram to represent the bonding in a metal.

Answer 29

Diagram should illustrate a sea of delocalised electrons with positive ions.

Question 30

State the properties of metals.

Answer 30

(Usually) high melting and boiling points; good conductors of electricity; malleable; ductile.

Question 31

Explain why metals usually have high melting and boiling points.

Answer 31

Strong covalent bonds between atoms require a lot of energy to break.

Question 32

Explain why metals are good conductors of electricity.

Answer 32

Delocalised electrons are free to move and carry the charge.

Question 33

Explain why metals are malleable and ductile.

Answer 33

Layers of ions can slide over each other without disrupting the structure.

Question 34

What is the definition of an alloy?

Answer 34

A mixture of elements, at least one of which is a metal.

Question 35

Explain why alloys are harder than pure metals.

Answer 35

Some ions in the alloy are of a different size, distorting the layers and making it more difficult for them to slide.

Question 36

What is the equation to determine the % of gold in an alloy?

Answer 36

number of carats / 24 × 100.

Question 37

State a use of aluminium.

Answer 37

Overhead electrical wiring, alloys for aircraft.

Question 38

State a use of copper.

Answer 38

Electrical wiring, plumbing, brass (when mixed with zinc), coinage.

Question 39

State a use of iron.

Answer 39

Bridges.

Question 40

State a use of magnesium.

Answer 40

Flares, high strength, low density alloys for aircraft.