Topic 4/14: Bonding Flashcards
Define volatility.
The tendency of a substance to vaporize
Define ionic bond.
- Electrostatic attraction between oppositely charged ions
- Only occurs between metals (positive charge) and non-metals (negative charge)
- Forms a neutral lattice
Outline physical properties of ionic compounds
- Low volatility (low tendency to vaporize)
- High melting temperatures
- Conduct electricity in molten state (freely moving ions)
- Soluble in polar substances
Define covalent bond.
- Electrostatic attraction between a shared pair of electrons and the positively charged nucleus
- Generally occur between non-metals
- Atoms with similar EN are likely to form a covalent bond (same affinity for electrons, no tendency to donate electrons)
Outline the strengths of electron repulsion.
Lone pair - lone pair > lone pair - bonding pair > bonding pair - bonding pair
Describe properties of diamond.
- Each carbon atom is joined to four other carbon atoms ➜ Giant covalent structure
- Tetrahedral structure held by strong covalent bonds
- High MP
- No delocalized electrons ➜ Low conductivity
- 109 angle
Describe properties of C60 fullerene.
- Sphere made of atoms arranged in a hexagon
- Covalent bonding and London dispersion forces
- Each carbon atom attached to three others
- Delocalized electrons ➜ Good conductivity
- 109~120 angles
Define sigma bonds.
Formed by the head-on overlap of orbitals
Define pi bonds.
Formed by the sideway overlap of adjacent p-orbitals
Formal charge equation
FC = V - (1/2B + L)
- V=Valence electron
- B=bonding electrons
- L=lone pair electrons
Define hybridization.
- A hybrid orbital results because of the mixing of different types of atomic orbitals on the same atom
- Four electron domains: sp3
- Three electron domains: sp2
- Two electron domains: sp
Outline characteristics of a polar molecule.
- Asymmetrical
- Polarities of polar bonds cannot cancel each other
Outline characteristics of non-polar molecules.
- Symmetrical
- Polarities of polar bonds can cancel each other
Define metallic bonding.
Electrostatic attraction between a lattice of positive ions and the delocalized sea of electrons
Outline the characteristics of metals.
- Malleable (layers of metals can slide over each other without breaking bonds)
- Ductile
- Good conductors of heat and electricity (delocalized electrons)
- Low EN values: lose electrons easily to form positive ions