electronegativity and intermediate bonding Flashcards
electronegativity
relative tendency of an atom in a covalent bond in a molecule to attract electrons in a covalent bond to itself
how is electronegativity measured?
pauling scale (0-4)
which are the most electronegative atoms?
F, O, N, Cl
which is the most electronegative element?
fluorine - 4.0
how is electronegativity affected across a period?
electronegativity increases across a period as the number of protons increases and the atomic radius decreases because the electrons in the same shell are pulled in more
how is electronegativity affected down a group?
it decreases down a group because the distance between the nucleus and the outer electrons increases and the shielding of inner shell electrons increases
what bonding would a compound containing elements of similar electronegativity and hence a small electronegativity difference have?
purely covalent bonding (less than 1.7)
what bonding would a compound containing elements of different electronegativity and hence a large electronegativity difference have?
ionic (more than 1.7)
what is the formation of a permanent dipole (polar covalent bond)?
- the elements in the bond have different electronegativities (of around 0.3 to 1.7).
- it has an unequal distribution of electrons in the bond
- produces a charge separation (dipole)
- delta negative and delta positive ends
what delta charge would the element with the larger electronegativity have?
delta negative
intermediate bonding
ionic and covalent are the extremes of a continuum bonding type. differences in electronegativity between elements can determine where a compound lies on this scale
permanent dipole
occurs in a molecule which is asymmetric and has one side which is more positive and one which is more negative.
