Please enable JavaScript.
Coggle requires JavaScript to display documents.
Chemical Bonding (Covalent Bonding (Properties of giant covalent compounds…
Chemical Bonding
Covalent Bonding
formed by the electrostatic attraction between a shared pair of electrons and the positively charged nuclei.
-
-
-
-
The “octet rule” refers to the tendency of atoms to gain a valence shell with a total of 8 electrons.
However, some atoms like Be and B, might form stable compounds with incomplete octets of electrons.
Resonance Structure
occur when there is more than one possible position for a double bond in a molecule. 
Shapes of species are determined by the repulsion of electron pairs according to VSEPR theory.
Linear
2 bonding pairs 0 lone pairs,180 degrees
Trigonal Planar
3 bonding pairs, 0 lone pairs, 120 degrees
Trigonal Pyramid
3 bond pairs, 1 lone pair, about 107 degrees
Tetrahedral
4 bond pairs, 0 lone pair, 109.5 degrees
Bent
2 bond pairs, 1 or 2 lone pairs, about 104 degrees
-
Intermolecular Forces
-
Hydrogen Bond: attractive force between the hydrogen attached to an electronegative atom of one molecule and an electronegative atom of a different molecule. Hydrogen usually bonds with oxygen, nitrogen, or fluorine to make a hydrogen bond.
Dipole-Dipole bond: force between an ion and a polar molecule. A hydrogen bond is an example of dipole-dipole force and is an attraction between a slightly positive hydrogen on one molecule and a slightly negative atom on another molecule.
London Dispersion Force: temporary attractive force that results when the electrons in two adjacent atoms occupy positions that make the atoms form temporary dipoles
Physical Property
-
-
Covalent compounds that are non-polar are insoluble in polar solvents unless thay are able to form hydrogen bonds with water.
-
Ionic Bonding
Physical Properties
-
conducts electricity when dissolved or molten, never conduct when it is a solid
-
-
Under normal conditions, ionic compounds are usually solids with lattice structures.
-
-
-
-
Metallic Bonding
-
-
-
Properties
Electrical Conductivity: Bonding electrons are delocalised; Current flow occurs without displacement of atoms within the metal
Malleability: Can be hammered into thin sheets;
atoms capable of slipping with respect to one another;
Melting Point
Melting (and boiling points) increase across the three metals because of the increasing strength of the metallic bonds.
-