Bonding Flashcards
What is a metallic bond?
The electrostatic attraction between a lattice of metal cations and a sea of delocalised electrons.
Why are metals malleable and ductile?
Layers of cations can slide over each other without breaking the metallic bonding.
What happens when a metal melts?
Regular repeating lattice of cations breaks down.
Cations able to flow over each other.
(Weaker metallic bonding)
Why does a metal with stronger metallic bonding have a higher melting point?
Requires more energy to weaken metallic bonds
What happens when a metal turns to gas?
No metallic bonding as all delocalised electrons localised to a specific cation.
Why do metals have higher melting and boiling points?
There is strong electrostatic attraction between cations and delocalised electrons.
Why does melting/boiling point of metals increase across a period?
Cations have higher charge, as have delocalised more electrons per ion.
So the electrostatic attraction in the lattice is stronger.
Why do metals not delocalise more electrons?
They only delocalise electrons in their outer shell.
Why does melting point decrease down a group?
Down the group, the size of the cation increases.
Larger cation = larger distance between cation’s nucleus and delocalised electrons.
Weaker attraction between cations and delocalised electrons.
What are alloys?
Metals made from two or more elements.
What are salts also known as?
Ionic compounds
What does the ionic model state?
The perfect ionic model states that ionic compounds are composed of cations and anions arranged in a lattice.
Define ionic bonding
The electrostatic attraction between cations and anions
Define electronegativity
An atom’s ability to attract electrons in a covalent bond.
How do we measure electronegativity?
Using the Pauling scale.
Higher number = more electronegative.
