Thinking (Electro) Negatively
CLASS SET!
Chemists wanted a way to measure the relative attraction for the pair of electrons shared between two
atoms. In 1932 Linus Pauling created the scale for electronegativity given above. The scale indicates
how strongly an atom attracts shared electrons. An atom with a large electronegativity attracts shared
electrons very strongly.
Part One: Electronegativity
Examine the table above and answer the following questions:
1. What happens to the electronegativity values across each period from left to right?
2. What happens to the electronegativity values up each group from bottom to top?
3. If you had a bond between a metal atom and a nonmetal atom, which of the two is more
electronegative? Explain your thinking.
4. Where are the atoms with the greatest electronegativity values located? Are they metals or
nonmetals?
5. Where are the atoms with the lowest electronegativity values located? Are they metals or
nonmetals?
6. Why do you think the noble gases have electronegativity values of zero?
7. Circle the atom in each pair below which will attract shared electrons more strongly:
a. C or Cl
b. Rb or Br
c. Ag or S
d. As or Na
8. If the difference in electronegativity is greater than 2.1, then the bond is considered ionic. Use
the electronegativity table above to create 3 (legit, neutral) compounds with ionic bonds.
9. If the difference in electronegativity is between 0.50 and 2.1, then the bond is polar covalent.
What does it mean to be polar covalent?
10. Use the electronegativity table above to create 3 (legit, neutral) examples of compounds with
polar covalent bonds.
Thinking (Electro) Negatively
CLASS SET!
11. If the difference in electronegativity is between 0 and 0.49, then the bond is nonpolar covalent.
What does it mean to be nonpolar covalent?
12. Use the electronegativity table above to create 3 (legit, neutral) examples of compounds with
nonpolar covalent bonds.
13. Metal atoms tend to form cations with positive charges. Is this consistent with the
electronegativity of metal atoms? Why or why not?
14. Do nonmetal atoms tend to form cations with positive charges or anions with negative charges?
Explain your thinking.
15. Sulfur forms both ZnS and SF2. Is sulfur the most electronegative element in both compounds?
Why or why not?
Part Two: Putting it all together
Complete the following chart:
Molecule
Total #
valence
e- in
molecule
CCl4
32
H2O
SiH2O
SiO2
NH3
HCF3
Lewis
Dot
Structure
Structural
Formula
Shape of
molecule
Bond
angle
Electronega
tivity
differences
for each
bond
Tetrahe
dral
109.
5o
Cl-C = 0.5
Draw
polarity
arrows
for each
bond
Is the
molecule
polar or
nonpolar
?
Will it
dissolve
in
water?
Can we
smell it?
Nonpol
ar
No
No