1) to learn about the characteristic properties of water. 2) to explain how and why water is...
TRANSCRIPT
1) To learn about the characteristic properties of water.
2) To explain how and why water is necessary for life on Earth.
The Properties of Water
Teachers' notesTeachers' notes
Biology
Water
The Wonders of Water
11-12
Basic chemistry and bonding
To learn about the properties of water that make life on Earth possible.
SubjectSubject
TopicTopic
TitleTitle
Grade(s)Grade(s)
Cross-curricular link(s)Cross-curricular link(s)
Prior knowledgePrior knowledge
Intended learning outcome(s)Intended learning outcome(s)
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.
Lesson notesLesson notes
The Wonders of Water
Why water?
Water provides an environment in which many biological reactions take place.
Water is involved in and is a common product of many biological reactions.
H
O
H
H
O
H
Water is PolarH2O
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.
O
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Water is polar. Show how polarity leads to hydrogen bonding between 8 different water molecules.
Water molecule
Hydrogen bond
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Ice is less dense than water
High surface tension
Strong cohesive properties
Universal solvent
Thermal properties
Properties of Water
Capillary Action
Hydrogen bonds
Polarity
specific heat capacity
acts as a thermalregulator
acts as a thermalregulator
1 Water is polar. This means that _____.
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
2 The partial positive and partial negative charges on a water molecule occur because of _____.
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
3 In a drop of water molecules, hydrogen bonds form between _____.
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
4 Cells are made of 70-95% water. In addition, cells are surrounded by water. As a result _____.
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
5 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?
A surface tension
B adhesion
C its thermal properties
D ice is less dense than water
E none of the above
6 Because molecules of water are farther apart in ice than in liquid form, _____.
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
7 Nonpolar molecules that do not interact with water molecules are called _____.
A covalent
B hydrophillic
C hydrophobic
D none of the above
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Water is polar. Show how polarity leads to hydrogen bonding between 8 different water molecules.
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Hydrogen bond
Water molecule
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.
Properties 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.