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Date:
Period:
Mickey Mouse Molecule
Background: Water is one of the simplest substances on Earth, and yet it is
something that we must have in order to live. A person can survive only about three
days without water. Water is so common to us that we often ignore some of its
simplest characteristics. Pure water is clear. It has no odor and no taste. These
are just three of the properties of water. There are many others that are less
obvious. For example, it takes a lot of heat to make water hot, and even more to
make it boil.
All of the properties of water can be explained by the way the water molecule is built. In every
water molecule 2 Hydrogen atoms are joined to 1 oxygen atom through chemical bonds. The bond
between the hydrogen and oxygen happens when the two atoms share 2 electrons between them—one
electron from hydrogen and one from oxygen.
In this activity, you will learn how hydrogen and oxygen are joined and also about some
characteristics of the bond between them. By understanding these 2 things, you can understand many
of the properties of water.
Objective: Construct a model of the water molecule learning/reinforcing the concepts of
polarity and hydrogen bonding.
Materials: 1 paper pattern, scissors, glue, markers/colored pencils (blue & red)
Procedure:
1.
Recall: The
molecular formula
for water is:
Color the hydrogen atoms blue and the oxygen atom red.
2. Using the periodic table & what you know of atomic structure fill in the information for the nuclei of 2
oxygen atoms & 4 hydrogen atoms.
3. Cut out the pieces (atoms, nuclei & electrons) of the water molecule. (DON’T WORRY about cutting
the electrons precisely BUT be careful not to lose any of your pieces.)
4. Sketch below the correct Bohr’s diagram for oxygen & hydrogen.
 Oxygen
* Hydrogen
5. Using the diagrams as a guide: glue the nuclei & electrons onto their corresponding atoms. You should
have 2 complete oxygen atoms & 4 complete hydrogen atoms when you’re finished.
a. Hint: You should have 20 electrons to complete this correctly. Remember to follow the energy
rules like your Bohr’s.
6. It wasn’t until the late 1900s that we learned the actual shape of the water molecule. It looks
somewhat like Mickey Mouse: with the oxygen being the head and the 2 Hydrogen atoms being the 2
ears. (See his picture above if you’re not familiar or need a refresher )
7. Now, based on this description glue the hydrogen and oxygen atoms together using a bond bridge for
two separate water molecule. The type of bond between hydrogen & oxygen is called a covalent bond
because the atoms are sharing their electrons. Be sure when you glue them together you turn the
atom to represent the location at which they are sharing.
Because of the way hydrogen and oxygen bond, each hydrogen atom has a slightly positive charge and the
oxygen has a slightly negative charge. You probably noticed that the electron from the hydrogen is
turned in towards the oxygen molecule. This leaves the nucleus (and it’s positively charged proton)
exposed when approached by another atom from the other direction. When an atom approaches the
oxygen atom it first encounters its remaining negatively charged electrons in the outermost shell. This
is characteristic of & called a polar molecule.
8. Draw a “+” sign & a “-“ sign on the appropriate sides of each of your water molecules.
Because water molecules are polar, they are naturally attracted to each other (“opposites attract”) &
tend to stick together. Water molecules stick together by forming a hydrogen bond between the
opposite charges. This “sticking together” is one reason why water requires so much heat to warm up
and even more to boil. It is also responsible for some of water’s other properties like surface tension,
adhesion and cohesion.
9. Use the hydrogen bond bridge & glue your 2 water molecules together. Remember: opposites attract.
Questions:
1. Name the elements found in a water molecule. ______________________________________
2. What is the ratio of the atoms of each element? _______________________
3. A molecule is a combination of atoms which are bonded together. How are the oxygen and
hydrogen atoms of water held together? What kind of bond do the share? ________________
_________________________________________________________________________
4. Water is described as being polar. What does than mean?
5. If one object has a positive charge and the other a negative, what will they tend to do to each
other? ____________________
6. Using your answer to Question 5, why do you think water molecules tend to “stick” together?
7. How are water molecules held together?
8. Name 3 properties water molecules have due to their polarity:
*
*
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Water Pattern Template (enough for 2 water molecules)
Hydrogen
Oxygen
Bonds (Bridges)
Covalent bond
Covalent bond
Covalent bond
Covalent bond
Hydrogen bond
Electrons
Nuclei
OXYGEN (double line):
____ P+
____ N
____ P+
____ N
HYDROGEN (single line):
____ P+
____ N
____ P+
____ N
____ P+
____ N
____ P+
____ N