Lewis Dot Structures - Practice Problems
Name _____________________________
1.
St.# _____
Draw Lewis Dot structures for each of the following elements:
*How many valence electrons does the element have?
Na
2.
Hr _____
F
Al
Ca
Cl
O
N
Draw Lewis Dot structures for each of the following molecules:
Step1 How many valence electrons does each atom have?
Step 2 How many total valence electrons does the compound have?
Step 3 Set up symbols/draw a skeleton structure…which atom is “central”?
(a)
(b)
the one with the lowest electronegativity (loses electrons most easily). Think of this as all
the other atoms swarming around it to take electrons.
or
the one with the highest valence. This means it will form the most bonds of any of the
atoms, so think of it as bonding with everything else around it. The other atoms can't sit
in the middle because they just won't form enough bonds.
Step 4 Connect symbols with single bonds (2 electrons in each).
Step 5 Fill around the “outer” atoms with electrons (6) first (note: never add electrons to H atoms!), then fill
around the central atom.
Step 6 If you don’t have enough electrons to fill around the symbols (8 - except for H – filled with 2)
start creating more bonds to share the electrons.
Step 7 Once all of the atoms have “full” structures the compound is neutral and you have finished.
a. H2
Total val e-____
e. HCl Total val e-____
b. Cl2 Total val e-____
f. H2O Total val e-____
c. OCl2 Total val e-____
g. PH3 Total val e-____
d. CI4 Total val e-____
h. SI2 Total val e-____
3.
Draw Lewis Structures for each of the following molecules and ions that contain double and triple bonds
a. CO2 Total val e-____
b. N2 Total val e-____
c. CO32- Total val e-____