Work through the list without notes. If you cannot do a statement, follow its link, then come back. Guide = study guide; Practice = practice questions.
Understanding
- I can explain why the O–H bonds in water are polar and why the bent shape makes the molecule polar but not charged. (Guide: “Polar covalent bonds”)
- I can draw two water molecules with δ⁺ and δ⁻ labels and show a hydrogen bond between them, distinguishing it from a covalent bond. (Guide: Figure 1; Practice Q3)
- I can explain how cohesion and adhesion allow water to be pulled up the xylem, and say what provides the pull. (Guide: “Cohesion, adhesion and transpiration”; Practice Q5)
- I can explain why ice floats and why this matters to organisms in lakes. (Guide: “Ice floats”; Practice Q3)
- I can explain how water dissolves ions and polar molecules, and why nonpolar substances are hydrophobic. (Guide: “Water as a solvent”; Practice Q1)
Calculation and skills
- I can use q = mcΔT to find energy or temperature change, with units on every line. (Guide: Worked example 1; Practice Q2)
- I can read a heating graph and use its gradients to compare specific heats. (Guide: Figure 2; Practice Q4)
- I can calculate a mean and a percentage change from repeated trials. (Guide: Worked example 2)
- I can calculate the cooling effect of evaporation using a heat of vaporization. (Practice Q7)
Reasoning
- I can identify the independent variable, dependent variable, control condition and controlled variables in a water-transport experiment. (Guide: Worked example 2; Practice Q5)
- I can explain why a correlation does not prove cause, and name a likely confounding variable. (Guide: Worked example 2; Practice Q6)
- I can link each property of water to its molecular cause and to a biological outcome, such as temperature buffering or evaporative cooling. (Guide: “From mechanism to biological outcome”; Practice Q6, Q7)
All ticked? Move on to Topic 1.2, Elements of Life, or return to the course roadmap.