2.11 - Metallic Bonding Flashcards
What are the general properties of metals?
- High melting temperatures
- Good electrical conductivity
- Good thermal conductivity
- Malleability
- Ductility
What type of ionisation energy do metals generally have?
Low
How many electrons do metals generally have in their outer shell?
One, two or three
Describe metallic bonding:
A lattice of metal ions surrounded by a sea of delocalised electrons
What about metallic bonding allows metals to conduct electricity?
The delocalised electrons
Why?
Because the electrons are free to move, and thus can carry a charge
Why are the electrons considered to be delocalised?
Because they are free to move and are not in fixed locations between cations
In order to melt an metal, what must happen?
The forces of attraction between the cations and delocalised electrons must be overcome
What is key about the structure of metals, in relation to these forces of attraction?
It is a giant lattice structure, so many of these forces need to be overcome for the metal to melt
What is the difference in melting temperatures for group 1 and group 2 metals?
Group 2 metals have higher melting points than group 1 metals
Why?
Because the number of delocalised electrons per cation increases
What about the d block metals?
They have even higher melting points because the number of delocalised electrons increases further
How do metals conduct electricity?
By the movement of the electrons towards the positive terminal of the cell
What property of metals makes them malleable and ductile?
The fact that the layers of metal ions can slide over each other under stress
