electronegativity

• what is the definition of electronegativity by the spec?

  electronegativity as the ability of an atom to attract the bonding electrons in a covalent bond
• how is electronegativity measured ?

  pauling scale
• how does electronegativity increase across the perodic table

  increases up and across the group and period respectively
• what are the factors affecting electronegativity ?

  nucleur charge

  atomic radius

  sheilding
• how does the nucleur charge affect electronegativity ?

  -the greater the nucleur charge (the more protons) the greater the attraction towards the nucleus then the greater the electronegativity
• how does atomic radius affect electronegativity ?

  the smaller the atomic radius,

  the smaller the number of shells,

  the smaller the distance between the nucleus and the shared pared of electrons

  so the greater the attraction,

  then the greater the electronegativity.
• how does shielding affect electronegativity ?

  smaller number of shells

  less repulsion from inner shell of electrons

  greater attraction towards shared electrons

  greater electronegativity
• how does electronegativity look across a period in terms of the factors ?

  electronegativity increases as

  nucleur charge increases

  atomic radius decreases

  shielding remains the same
• what is a non polar bond ?

  electrons are shared equally

  the electronegativity values are relatively the same

  if its the same atom (br2) its called pure covalent bond

  the dipoles cancel eachother out and the shape is therefore symetrical
• what is a polar bond ?

  electrons are shared unequally

  required polar bonds with dipoles that do not cancel out due to their direction

  the molecules containing covalently bonded atoms have different electronegativity
• covalent bond has a electronegativity difference of

  0
• a polar covalent bond has a electronegativity difference of

  0 to 1.8
• a ionic bond has a elevtronegativity difference of

  greater then 1.8
• if the charge is distrubuted unequally over a whole molecule what dipole does the molecule have

  permenant dipole as the dipoles dont cancel each other out
• what is a dipole ?

  separation of opposite charges
• in a HCL bond there is a difference in electronegativity explain what happens in terms of polarity

  the hcl bond is polarised wth a small positive partial charge on the hydrogen atom and a small negative partial charge on the chlorine atom due to the difference in electronegativity