Download WS for 10/14 Sun (dot structures, geometry)

Lewis Dot Structures,
Molecular Geometries
Supplemental Instruction
Iowa State University
Leader:
Course:
Instructor:
Date:
Danielle
Chem 167
Schewe-Miller
10/14/12
1. Indicate how many valence electrons are in the following compounds/elements.
 C
___ electrons
 F
___ electrons
 SO2
___ electrons
 CH3
___ electrons
3 PO4
___ electrons
 NH4+
___ electrons
2. Draw Lewis structures for the following compounds.

CS2

SCl2

SeI4

XeF2

NO2-
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3. Draw the Lewis dot structure for SF4. How many lone pairs are there? How many total
bonding sites are there?
4. What is the molecular geometry of SF4? What would it be if there was one more lone
pair?
5. In each group of three bonds, circle the one which is most likely to be polar.

C–H
O–H
S –H

C – Cl
Cl – Cl
H – Cl

F–F
O–F
C–F

N–H
N–O
N – Cl
6. Fill in the blanks or circle the correct term.

Bonds are likely to be ionic if there is a great/small difference in
________________ between the atoms.

When a structure can be represented in multiple ways, we say that it has a
certain number of ______________ structures.

The concept of an atom trying to have ____ valence electrons is called the
_______________ rule.

The attraction of an atom for the shared electrons in a covalent bond is called
___________________.
7. Some exceptions to the octet rule:
 Hydrogen and Helium are stable with only ____ electrons.
 Beryllium (Be) is stable when surrounded by ____ electrons.
 Boron (B) is stable when surrounded by ____ electrons.