Lecture 3 - Atomic Bonds Flashcards
Properties of Bohr model of the atom
Nucleus contains protons and neutrons
Protons and neutrons have the same charge
Electrons revolve around in defined discrete orbits
E and P have the same charge
N.O of E is the same as the N.O of protons with exceptions to ions
Properties of Bohr model of the atom 2
Nucleus provides mass
Electrons can jump between orbits gaining or losing electrons
Energy is absorbed or emitted as an optical photon
Electrons have negative charge
Protons have positive charge
What does it mean in terms of electrons when electrons can behave like a wave or a particle
Electrons around the nucleus are in atomic orbitals defined by spatial probability distribution
And each orbital at discrete energy level is defined by quantum numbers
What are the 3 primary types of bonds
Ionic
Covalent
Metallic
What are the 2 types of secondary bonds
Van der waals
Hydrogen bonds
What is covalent bonding
Sharing of electrons
2 atoms combine and share electrons
What can covalent bonds be regarded as
As linear combination of atomic orbitals
3 properties of covalent bonds
Very strong
Lead to stiff materials with high mots e.g diamond
Bonds are generally sp3 hybrids therefore directional (sp3 hybrid is basically a tetrahedral shape)
What does metallic bonds occur in
Metals
Metal alloys
Some semiconductors
How are electrons bound to each other in metallic bonds
Outer electrons are weakly bound to metal atoms and they leave the nuclei to wander around the solid.
What type of bond has delocalised electrons
Metallic bonds
3 properties of metallic bonds
The positive nuclei are in a sea of negative electrons
No directonalilty
High electrical and heat conductivity
How are van der waals forces formed
From dipole dipole attraction between noncharged atoms
What does all van der waals forces experience
Constant vibrational motion
Hydrogen bond determined what structure
Ice structure
