LEWIS STRUCTURES: formulas which symbols
represent nucleus & inner shell electrons; dot pairs or dashes
represent electron pairs in covalent bonds
1. ____________________: (lone pair) pair of electrons that is not involved in bonding &
belongs to only one atom
2. ____________________: shows atoms, bonds, & arrangement, but not lone pairs of e-
3. ____________________: produced when one pair of e- is shared b/n two atoms
4. MULTIPLE BONDS: stronger & shorter than single bonds
a. Double Bond: produced when _____ pairs of e- are shared b/n two atoms
1) shown by either 2 side-by-side pairs of dots
2) or by 2 parallel dashes
b. __________ Bond: produced when 3 pairs of e- are shared b/n two atoms
1) shown by either 3 side-by-side pairs of dots
2) or by 3 parallel dashes
STEPS FOR DRAWING LEWIS STRUCTURES
1. Count the total
number of valence electrons in the compound.
C: 1 x 4 e- = 4
Cl: 4 x 7 e- = 28
2. Draw the symbols
for the elements with the central atom in the middle.
(The central atom is the one that is written first, except hydrogen will never be central.)
3. Connect the
surrounding atoms to the central atom with a pair of electrons.
Had 32 e- to start (step 1)
Used 8 e- to connect
Have 24 e- left
4. Put electrons
around surrounding atoms until all have 8 electrons around them.
(Exception: Hydrogen will only have 2 e- around it.)
Have 24 e- left
Used 24 e- to complete surrounding
Have 0 e- left to use
5. If there are any electrons left over, put them on the central atom.
6. Check to make sure that all atoms have 8 electrons around them.
7. If there are not
enough electrons to give all atoms 8 electrons around them, try multiple