BUILDING COVALENT MOLECULES: ANSWERS
1. In covalent molecules the electrons are shared so that each atom can get a full valence shell.
2. The sharing of electrons is always done in pairs of electrons.
Number of shared electrons
Name of bond
Shown in a structural formula by
what symbol?
2
4
6
SINGLE
DOUBLE
TRIPLE
----===
===
Shown in a model by how
many of what item?
ONE STICK
TWO SPRINGS
THREE SPRINGS
3. We will be using the following elements when we build covalent compounds:
Element
Color
Lewis Dot
Number of covalent bonds
needed to get a full outer shell
= number of holes
C
BLACK
4
H
O
YELLOW
RED
1
2
S
SILVER
2
N
BLUE
3
4. Suppose you need to make three covalent bonds to get a full outer shell. What are three ways of covalent bonding involving combinations of
single, double, and triple bonds that you could use?
5. When you build a good model what happens to the holes in the atomic models?
THEY ARE FULL
6. Now let’s build some molecules! Build each of these molecules and keep them intact throughout the entire lab.
Molecule’s name
water
What is used for or where is it
found?
F: Atmosphere Crust Living Things
Oceans Lakes Wells Aqua firms
Uses: Respiration Photosynthesis
Chemical Formula
H2O
oxygen
Atmosphere Crust Living things
Uses: Rocket Boosters And Fuel
respiration photosynthesis Cryo-Storage
O2
nitrogen
Atmosphere Living Organisms
Plant food gunpowder rocket fuel
ammonia
N2
methane
Earths Crust deep in the ocean
Heating cooking Car fuel
CH4
propane
Earths Crust
Fuel power grills
C3H8
butane
Fossil Fuel
Cooking fuel lighters aerosol spray
C4H10
rotten egg gas
Product of decaying
Uses: Law enforcement , Small
amounts used in certain novelty
items
H2S
ammonia
Sea water salt marshes
Uses: Fertilizer cleaner explosives
chemical warfare (mustard gas)
Atmosphere
Uses: Photosynthesis Propellant
Paintball Airsoft
NH3
carbon dioxide
CO2
Structural formula