1.4.9 Properties of Metallic Substances

Question 1

Metals form

Answer 1

giant metallic lattices

Question 2

Metals form giant metallic lattices in which the metal ions are surrounded by

Answer 2

a ‘sea’ of delocalised electrons

Question 3

The metal ions are often packed in

Answer 3

hexagonal layers or in a cubic arrangement

Question 4

Layers of copper ions (the delocalised electrons are not shown in the diagram)

Answer 4

Question 5

If other atoms are added to the metal structure, such as carbon atoms, this creates

Answer 5

an alloy

Question 6

Alloys are much stronger than pure metals, because

Answer 6

the other atoms stop the layers of metal ions sliding over each other easily

Question 7

The strength of the metallic attraction can be increased by:
- Increasing the number of

Answer 7

delocalised electrons per metal atom

Question 8

The strength of the metallic attraction can be increased by:
- Increasing the

Answer 8

positive charges on the metal centres in the lattice

Question 9

The strength of the metallic attraction can be increased by:
- Decreasing

Answer 9

the size of the metal ions

Question 10

Metallic compounds are

Answer 10

malleable

Question 11

When a force is applied

Answer 11

the metal layers can slide

Question 12

The attractive forces between the metal ions and electrons

Answer 12

act in all directions

Question 13

So when the layers slide, the metallic bonds are

Answer 13

re-formed

Question 14

The lattice is not broken and has

Answer 14

changed shape

Question 15

Atoms are arranged in layers so the layers can slide when force is applied diagram

Answer 15

Question 16

Metallic compounds, as well as malleable, are

Answer 16

strong and hard

Question 17

Metallic compounds are strong and hard, due to

Answer 17

the strong attractive forces between the metal ions and delocalised electrons

Question 18

Metals can

Answer 18

conduct electricity when in the solid or liquid state

Question 19

In the solid and liquid states, there are

Answer 19

mobile electrons which can freely move around and conduct electricity

Question 20

When a potential difference is applied to a metallic lattice, the delocalised electrons

Answer 20

repel away from the negative terminal and move towards the positive terminal

Question 21

As the number of outer electrons increases across a period, the number of

Answer 21

delocalised charges also increases

Question 22

As the number of outer electrons increases across a period, the number of delocalised charges also increases:

Answer 22

Sodium = 1 outer electron
Magnesium = 2 outer electrons
Aluminium = 3 outer electrons

Question 23

Therefore, the ability to conduct electricity also

Answer 23

increases across a period

Question 24

How metals conduct electricity diagram

Answer 24

Question 25

Since the bonding in metals is

Answer 25

non-directional

Question 26

Since the bonding in metals is non-directional, it does not really matter how

Answer 26

the cations are oriented relative to each other

Question 27

Metals are good

Answer 27

thermal conductors due to the behaviour of their cations and their delocalised electrons

Question 28

When metals are heated, the cations in the metal lattice

Answer 28

vibrate more vigorously as their thermal energy increases

Question 29

These vibrating cations transfer their

Answer 29

kinetic energy as they collide with neighbouring cations, effectively conducting heat

Question 30

The delocalised electrons are not bound to

Answer 30

any specific atom within the metal lattice and are free to move throughout the material

Question 31

When the cations vibrate

Answer 31

they transfer kinetic energy to the electrons

Question 32

The delocalised electrons then carry

Answer 32

this increased kinetic energy

Question 33

The delocalised electrons then carry this increased kinetic energy and

Answer 33

transfer it rapidly throughout the metal, contributing to its high thermal conductivity.

Question 34

Metals have high

Answer 34

melting and boiling points

Question 35

Metals have high melting and boiling points, this is due to

Answer 35

the strong electrostatic forces of attraction between the cations and delocalised electrons in the metallic lattice

Question 36

Metals have high melting and boiling points, these require

Answer 36

large amounts of energy to overcome

Question 37

Metals have high melting and boiling points, as the number of

Answer 37

mobile charges increases across a period, the melting and boiling points increase due to stronger electrostatic forces