Electronegativity is the tendency of an atom to attract electrons in a bond. Atoms with higher electronegativity values attract electrons more strongly. Ionic bonds form between metals and nonmetals when the nonmetal has a higher electronegativity and takes electrons from the metal. Covalent bonds form between nonmetals which share electrons. Covalent bonds can be polar or nonpolar depending on the difference in electronegativity values and molecular geometry. Hydrogen bonds form between polar molecules with partial charges, such as between hydrogen and oxygen or nitrogen.

1. *Bonding

2. *Electronegativity: the tendency of an atom to
attract electrons
*The higher the electronegativity, the stronger
the atoms attraction for electrons
*The values range from 0.6-4.8
*Atoms will gain, lose or share electrons when
they bond depending on the relative
electronegativity's of the atoms participating in
the bond.
*Metals have low electronegativity's
*Non metals have high electronegativity's
*Electronegativity

3. *Ionic Bonding
*Ionic bonds form between metals and
nonmetals and result in the formation of ions
*Ions are atoms that have gained or lost
electrons and are therefore charged
*Nonmetals have higher electronegativity’s so
they will take electrons from metals

4. *Ionic Bonding

5. *Covalent Bonds
*Covalent bonds form between nonmetals
*Nonmetals all have relatively high
electronegativity’s so they share electrons
*Electrons being shared are represented by a
straight line

7. *Covalent Bonds
*Covalent bonds are either nonpolar or polar
depending on the electronegativity’s of the
nonmetals and their 3-D arrangement in space
*Nonpolar covalent bonds form when electrons
are equally shared
*Polar covalent bonds form when electrons are
not equally shared
*Polar covalent bonds contain atoms (or ends of
a molecule) with partial charges

8. *Polar and nonpolar
*H2O and H2CO are polar
*CO2 is nonpolar

9. *Hydrogen Bonds
*A hydrogen bond is a slight attraction of a
hydrogen on one molecule to a nitrogen or
oxygen on another molecule.
*Hydrogen bonds occur between polar molecules
since they have partial charges
*Hydrogen bonds are represented with dashed
lines

10. *All of the dashed lines below are hydrogen bonds
*The solid lines are covalent bonds.
*Are these covalent bonds polar or nonpolar? How do
you know?

11. *The bonds have to be polar since hydrogen
bonds are being formed.
*Oxygen atoms and nitrogen atoms will always
have a partial negative charge in a hydrogen
bond.
*Hydrogen atoms will always have a partial
positive charge in a hydrogen bond.