Connect the Dots
Nonmetal atoms bond covalently. The bonding tendencies of nonmetal atoms are directly related to the
number of valence electrons they have. Lewis Dot symbols keep track of the valence electrons of different
atoms. In covalent bonds, atoms share pairs of electrons, so only unpaired valence electrons available for
bonding. We can use Lewis Dot symbols and the HONC 1234 rule to construct accurate structural formulas.
Website Link: Lewis Dot Puzzle Pieces – Computer Simulation
http://content.bfwpub.com/webroot_pubcontent/Conte
nt/BCS_5/Stacy_Living%20By%20Chemistry%201e/Lewis
%20Dot%20Puzzle%20App/LDP-5release_updated/LewisDotRedirect.html
Instructions: The puzzle pieces on the left represent Lewis Dot symbols. they show how many valence
electrons an atom of that element has. Notice that some electrons are paired whereas others are unpaired. In
the drawing below, each H atom puzzle piece has one unpaired electron; the N atom has two paired electrons
and three unpaired electrons. Atoms combine to form molecules where all the electrons are paired. The puzzle
pieces allow you to pair up electrons and create molecules.
Practice
Step 1: Click on the practice mode above at the top center of the screen.
Step 2: Click and drag an “N” and three “H” puzzle pieces over to the empty area to the right.
Step 3: Connect the puzzle pieces like shown above and watch the pieces change as they fit together.
If they do not connect, then it is not the correct way to connect the atoms. Click on a piece, or atom,
and drag it where you need it. Also use the two arrows given to help rotate the atoms.
Step 4: In the top right corner, use the pull down menu to find NH3. Then click on the check molecule
box to see if you are correct. If correct, use the clear button to clear the screen.
Part I: Create Molecules
1. Use the puzzle pieces to construct the molecules given below. Then draw, in each box, the Lewis dot
structures for each molecule, leaving off the outline of each puzzle piece (like the last picture above to the right).
PH3
HOCl
F2
CH3Cl
2. Use the puzzle pieces to create more molecules following the directions. For each molecule, draw the Lewis
dot structure and write the molecular formula.
a. Use one S and as many Hs as you
need.
b. Use one Si and as many Fs as you
need.
c. Use two O s and as many Hs as
you
need.
Molecular formula:
Molecular formula:
Molecular formula:
3. Use the puzzle pieces to construct a molecule with the molecular formula C2H6. Draw its Lewis dot
structure and its structural formula (show bonds between atoms as lines).
Lewis dot structure:
Structural formula:
4. Use the puzzle pieces to construct all 3 possible isomers of C3H8O. Draw Lewis dot structures for each
isomer. Do the molecules follow the HONC 1234 rule?
Isomer #1
Isomer #2
Isomer #3
5. Use the puzzle pieces to construct the following molecules. Draw both the Lewis dot structures and the
structural formulas (show bonds between atoms as lines).
Lewis dot structure:
H2S
CH4
NI3
NO2-
N2
C2H2
CH3CH2CCH
Structural formula:
Cl2CH2
H3NBF3
CH3CH2OH