The Properties of Water
1) To learn about the characteristic properties of water.
2) To explain how and why water is necessary for life on
Earth.
Teachers' notes
Subject
Topic
Title
Grade(s)
Biology
Water
The Wonders of Water
11-12
Cross-curricular link(s)
Prior knowledge
Intended learning outcome(s)
Basic chemistry and bonding
To learn about the properties of water that make
life on Earth possible.
Lesson notes
Slide 4: Drag the water molecules to reveal why water is essential.
Slide 6: Drag the "Hydrogen Bonds" and "Water Molecule" to the bottom right of the page. The
bonds and water molecules are infinitely cloned in order for students to show hydrogen bonding
between different water molecules. The water molecule at the top of the page will link to one
example of an "answer" for this. From the link page, click on the water molecule at the bottom of
the page to return to Slide 7.
Slide 7: Allow students time to complete the table on the properties of water. At the end of the
allotted time, click on the watering can to link to the "answer" page. There are many answers to
these, so allow extra information to be added to the table. Once you have reviewed the "Answer"
slide, click on the water molecule at the top of the page to return to the Senteo quiz questions.
The Wonders of Water
Why water?
Water is involved in and is a common product of many
biological reactions.
H
O
H
Water
provides an environment in which many biological
H
reactions
take place.
O
H
Water is Polar
H2O
Water is held together by covalent bonds, but oxygen keeps the electrons around
it more than the hydrogens do. The result...oxygen has a slight negative charge
while hydrogen has a slight positive charge.
Water is polar. Show how polarity leads to hydrogen bonding between 8
different water molecules.
Hydrogen bond
-
-
O
-
-
H
H
-
+
+
O
O
H
H
+
+
H
H
+
-
-
+
-
-
O
O
H
+
H
H
+
+
H
+
Water molecule
Properties of Water
Ice is less dense than water
High surface tension
Strong cohesive properties
Universal solvent
Thermal properties
Capillary Action
Hydrogen bonds
Polarity
specific heat capacity
acts as a thermal
regulator
acts as a thermal
regulator
Water is polar. This means that _____.
1
A
the opposite ends of the water molecule have opposite
electrical charges
B
water molecules are linear.
C
water is just one of the many hydrophobic molecules
D
all of the atoms in a water molecule have equal
electronegativities
E
all of the above
The partial positive and partial negative
charges on a water molecule occur
because of _____.
2
A
the unequal sharing of electrons between the oxygen and
the hydrogen atoms in a water molecule
B
the stability of one atom of a bond but not the other atom
C
covalent bonding
D
ionic bonding
E
hydrogen's high electronegativity
In a drop of water molecules, hydrogen
bonds form between _____.
3
A
two oxygen atoms in different water molecules
B
the hydrogen atoms in two different water molecules
C
the hydrogen atom in one water molecule and a oxygen
atom in another water molecule
D
the hydrogens in a single water molecule
E
none of the above
Cells are made of 70-95% water. In
addition, cells are surrounded by water. As
a result _____.
4
A
the temperature of living things changes relatively slowly
B
a variety of nutrients are available as dissolved solutes
C
waste products can be easily removed
D
dissolved substances can be easily transported within
cells or between cells in multicellular organisms
E
all of the above
You fill a glass of water to just slightly
above the rim without it spilling over the
glass. What property of water best
explains this?
5
A
surface tension
B
adhesion
C
its thermal properties
D
ice is less dense than water
E
none of the above
Because molecules of water are farther
apart in ice than in liquid form, _____.
6
A
ice floats
B
ice is denser than liquid water
C
ice expands when it melts
D
ice vaporizes before liquid water does
E
all of the above
Nonpolar molecules that do not interact
with water molecules are called _____.
7
A
covalent
B
hydrophillic
C
hydrophobic
D
none of the above
Water is polar. Show how polarity leads to hydrogen bonding between 8
different water molecules.
-
-
-
-
O
O
-
H
H
-
H
H
+
+
+
+
O
-
H
+
-
O
O
+
+
-
-
-
H
H
H
H
+
+
-
-
-
O
H
H
+
+
H
+
-
O
H
+
H
+
+
O
O
+
-
H
H
H
-
-
Hydrogen bond
H
+
Water molecule
+
Properties of Water
Ice is less dense than water
Ice floats and insulates
underlying water
High surface tension
Water drops form on surfaces
and runs off
Strong cohesive properties
Water does not pull apart
easily
Universal solvent
Medium for most biological
reactions
Thermal properties
Much energy is necessary to
change temperatures in large
bodies of water.
Capillary Action
Cohesion and adhesion allow
water to move against gravity
in plants/trees.
Hydrogen bonds
Individually, relatively weak;
collectively very strong.
Polarity
Allows for the formation of
hydrogen bonds between
other water molecules as well
as different molecules.