U2 - metallic bonding

What is a metallic bond

When a bond occurs between the same one type of cation. Electrostatic forces of attraction between the positively charged metal cations and negatively charged valence electrons occur in all directions, holding the lattice together.

Where does metallic bonding occur

It occurs in pure metals and metal alloys

Where does metallic bonding come from

It comes from metals shedding their valence electrons since they lose their outer shell easily, but since there is no anion the electrons just float around the cations.

eg. 3 sodium sheds 3 electrons

What is the delocalised sea of electrons

Many electrons that move around the bonded cations, they are mobile and randomly move around.

What does energy do to the electrons

Energy pushes electron in one singular same direction since they normally move randomly

How does metallic bonding become an crystal lattice

When electron shedded from the metals overlap each other to make a sea of electrons, causing the cation and electrons to be attracted. The attraction between cation and electrons everywhere that holds the bond together

What is a crystal lattice

Only made up of bonded cation that are close together and touch with a sea of electron all around

What is the best description for the sea of electrons

Random and mobile electrons that move all throughout the crystal lattice.

Are metallic bonds easy to seperate

They are hard to seperate but easy to move as they are malleable since the sea of electrons neutralises the repulsion of two cations next to each other so they can slide around without separating.

What are alloys

Alloys are a mixture of two or more elements where one element is a metal, combined via metallic bonding.

Why are alloys harder to break

Alloys are harder than pure metals since the cations are different sizes due to the atomic radius (distance from nucleus to valence electron)