electronegativity

• what is electronegativity

  the power of an atom to attract the electrons in a covalent bond
• when two of the same element are bonded the electrons are in the middle of the two atoms as they both have the same electronegativity
• when there are two different elements electrons are closer to the atom with the stronger electronegativity
• atoms with a stronger nuclear charge have more protons so have a stronger attraction between the nucleus and bonding pair of electrons meaning a high electronegativity
• a smaller atomic radius means the bonding electrons are closer to the nucleus so there is a stronger attraction so a higher electronegativity
• less shells of electrons causes a high electronegativity as there's less shielding of the nucleus meaning there's a stronger attraction between the nucleus and bonding electrons
• electronegativity decreases down the group as the atomic radius increases and there's more shielding so less attraction between the nucleus and bonding electrons
• polar solvent 


  dissolves ionic or polar molecules the best
• non-polar solvent 


  mainly used to dissolve organic molecules
• polar covalent bond

  when the bonded atoms are different and have different electronegativity values
• dipole 


  the separation of opposite charges