Lecture 8-Covalent bonding Flashcards
What does bonding determine?
The SHAPE of molecules
-interactions between proteins / receptors / drugs
What can cause permanent enzyme inhibition?
COVALENT bonding
What does polarity determine?
- Intermolecular forces
- Properties
- Solubility
- Receptor interactions
What is covalent bonding?
E- pairs are shared by both the participating atoms
What does it mean if the e- pairs in a covalent bond are localised?
They’re in a definite space between the nuclei of the 2 atoms
Is the covalent bond a directional bond?
YES
How is a covalent bond established?
Between atoms of the same / different non-metallic elements
Where does the shared e- pair spend most of its time in a covalent bond?
Between the 2 nuclei
How is a covalent bond formed?
By ELECTROSTATIC ATTRACTION between oppositely charged nuclei + shared e-
Why do atomic orbitals overlap?
To form molecular orbitals
What are molecular orbitals?
Linear combinations of atomic orbitals?
What must remain the same when atoms interact to form molecules?
The overall number of orbitals
What factors favour covalent bonding?
- HIGH ionisation energies
- EQUAL e- affinities
- EQUAL/SIMILAR electronegativity
- HIGH NUCLEAR CHARGE
- SMALL atomic size
What are non-polar bonds?
Between 2 atoms of equal / similar electronegativity
What are polar bonds?
Between 2 atoms of significantly different electronegativity
What do polar bonds affect?
The REACTIVITY of the bond + types of intermolecular forces
What leads to a pure non-polar covalent bond?
NO electronegativity difference
What leads to a pure polar covalent bond?
SMALL electronegativity difference
What leads to an ionic bond?
A LARGE electronegativity difference
What type of conductor is silicon?
a semi-conductor
How do you name covalent compounds?
2nd element = -ide
prefix = indicates n.o of atoms
