Structure And Bonding Flashcards
What is bonding?
The nature of attractions which hold atoms, ions or molecules together
Starting with the strongest list the types of bonding:
Ionic, metallic and covalent
Hydrogen
Permanent dipole-dipole and London
What is the structure?
The way in which atoms are arranged in space
What is a lattice?
A regular network or atoms/ions in a 3D arrangement in a solid state
What is a giant lattice?
Strong bonds that extend throughout the lattice structure
What is a simple lattice?
Weak forces that extend throughout the lattice structure
What is a simple molecular lattice?
A 3D structure of simple molecules held in place weakly by intermolecular forces
What are the properties of a molecules with a simple molecular lattice?
- Low melting and boiling points as the intermolecular forces are weak
- Do not conduct electricity- as neutral
- Dissolve best in solvents with the same type of intermolecular forces
What is a giant covalent lattice?
A 3D structure of atoms held in place by strong covalent bonds which extend throughout the solid structure
What are the properties of a giant covalent lattice?
- Very high melting points as covalent bonds are strong
- Do not conduct electricity as atoms are neutral
- Do not dissolve in any solvent as no new attractions can form between the atoms and solvent molecules
What are 3 examples of a giant covalent lattice?
- Diamond- (typical giant covalent structure and properties) every carbon atom bonds to 4 other with a tetrahedral arrangement
- Silicon (same as diamond yet with Si atoms)
- Graphite (ANOMALOUS)
Every carbon atoms bonds to 3 other so has delocalised electrons, allowing it to conduct electricity.
The graphene layers are strong separately yet graphite is soft due to weak intermolecular London forces holding the layers together
What is metallic bonding? And how does it change across a period?
The attraction between positive metal ions and delocalised electrons.
The strength increases as the nuclear charge increases.
What are delocalised electrons?
Electrons shared between 2 or more atoms that are free to move
What is a giant metallic lattice?
3D structure of metal atoms held in place by strong metallic bonds
What are the properties of a giant metallic lattice?
- High melting and boiling points- as strong metallic bonds
- Can conduct electricity as delocalised electrons are free to move
- Insoluble in solvents- as metal atoms are unable to form new attractions with solvent molecules