Chap 3: Metallic Bonding

Question 1

What is metallic bonding?

Answer 1

The electrostatic force of attraction between delocalised electrons and cations in a metallic lattice structure

Question 2

What does the metallic bonding crystal lattice model look like?

Answer 2

Electrons removed from the valence electrons are able to move freely within the crystal lattice structure between the metal cations. This is called the sea of delocalised electrons.

The electrostatic attraction between the delocalised electrons and the metal cations holds the cations closely to one another, maintaining the structure of the metal

Question 3

Why are metals malleable?

Answer 3

When a mechanical force is applied on metals , the layers of cations are able to roll over each other, while still being held in place by the electrostatic force of attraction

Question 4

Why are metals considered good heat conductors?

Answer 4

metal absorbs heat, rise in temp causes an increase of kinetic energy –> metallic ions vibrate more rapidly and delocalised electrons can move faster transferring the kinetic energy to nearby ions and electrons –> creates a chain reaction allowing for the heat to be passed through

Question 5

Why are metals hard and have high melting and boil points?

Answer 5

They have a strong non-directional electrostatic force of attraction that holds the metal cations and sea of delocalised electrons together in all directions. Therefore a large amount of heat is needed to break the bond

Question 6

What are the limitations of the metallic bonding model?

Answer 6

• different melting and boiling points of different metals
• the difference in electrical conductivity of different metals
• magnetic properties shown by iron, nickel and cobalt