2.2: Water
Teaching time: 2 hours Practical time: 0 hours
key vocabulary
prior learning & retrieval practice
Review 1.2 ultrastructure of cells
Review 2.1 molecules to metabolism
water
U1: Water molecules are polar and hydrogen bonds form between them.
Exercise 1: Read this article and explain how water molecules are polar and how this polarity allows hydrogen bonds to form between them.
NoS: Use theories to explain natural phenomena—the theory that hydrogen bonds form between water molecules explains the properties of water. (2.2)
A1: Comparison of the thermal properties of water with those of methane.
Exercise 2: Watch this video and complete a table that compares and contrasts properties of water and methane.
Guidance from the syllabus: Comparison of the thermal properties of water and methane assists in the understanding of the significance of hydrogen bonding in water.
wonderful water molecule exercise.pdfEssential idea: Water is the medium of life.
U2: Hydrogen bonding and dipolarity explain the cohesive, adhesive, thermal and solvent properties of water.
A2: Use of water as a coolant in sweat.
A3: Modes of transport of glucose, amino acids, cholesterol, fats, oxygen and sodium chloride in blood in relation to their solubility in water.
Exercise 3: Use the article called “The Wonderful Water Molecule” and your textbook to answer the following questions:
• Describe, with the help of diagrams, how the distribution of electrons results in the
structure and polarity of the water molecule.
• Molecules with small molecular mass are usually gases at room temperature. Explain
why water is unusual.
• How does the bonding between water molecules change with temperature.
• List 5 other key properties of water that you have learned from reading the article.
Guidance from the syllabus:
Students should know at least one example of a benefit to living organisms of each property of water.
Transparency of water and maximum density at 4°C do not need to be included.
U3: Substances can be hydrophilic or hydrophobic.
Exercise 4: Copy and complete this table
