Electronegativity
Definition
It is a measure of the attraction of the nucleus for a pair of electrons in covalent bond
Periodic Table
It increases from left to right across each period of the table
In lower periods they have more protons, there is a decrease in electronegativity
Every period has an extra layer of electrons, called a shell, added around the nucleus.
Intramolecular
Attractions between atoms of molecules depend on the extent that electrons are gained or lost or shared
Depends on the formation and mobility of Ions, and the strength, hardness and density of ionic solids
Intermolecular
Involve various competing interactions between electrons and nuclei of different molecules
These interactions determine whether the generally smaller molecules of covalent molecular substances are solids, liquids or gases at room temperature
Determine properties
Dispersion forces
Interactions between charged subatomic particles of any two neighboring atoms
Examples
Can be induced by the closeness of other local charged particles, for example ions
Attraction between the electrons of one atom and the protons in the nucleus of a neighboring atom
Repulsion between the cloud of negatively charged electrons surrounding each nucleus
Repulsion between the positively charged nuclei of neighboring atoms
Dipole - Dipole forces
The elements of their composition and their shape affect whether molecules will have Dipole - Dipole forces
The more electronegativity atom will attract the electrons of the bonded atom more strongly
Molecules with identical atoms, like diatomic gases (H2, O2 and halogen gases) cannot be polar