Water Powers Worksheet
Biology & Chemistry Core Science Concepts
Water Powers Worksheet
Investigating Polarity, Cohesion, Adhesion, Solutes, and Solvents
Name:
Date:
Period:
1
The Foundation: Molecular Polarity
O δ− (Partial −) H δ+ H δ+ Water Molecule (H2O)
Polarity is an uneven distribution of electrical charge within a molecule. Oxygen is highly electronegative, pulling shared electrons closer to its nucleus, creating a partially negative pole (δ−) near oxygen and partially positive poles (δ+) near hydrogen.
Key Effect: Opposite partial charges attract neighboring water molecules, forming weak but essential hydrogen bonds.
Guided Check: Why does water's bent shape and polar covalent bonding allow it to form hydrogen bonds with other water molecules?
2
Forces of Attraction: Cohesion vs. Adhesion
Cohesion (Water ↔ Water)
Same Substance
Attraction between identical water molecules through hydrogen bonding. Causes droplets to form domes and produces surface tension.
Visual Proof: Water striders walking on pond surfaces; beading on waxy leaves.
Adhesion (Water ↔ Other)
Different Substances
Attraction between water molecules and other polar or charged surfaces. Powers capillary action in narrow tubes.
Visual Proof: Curved meniscus in glass graduated cylinders; paper towels absorbing spills.
Scenario Analysis: Identify whether each phenomenon is caused primarily by Cohesion, Adhesion, or Both, then write a brief justification.
A. Morning Dew on a Spiderweb
Water forms tight spheres clinging to thin silk threads.
Type: ______________
Reason: ____________________
B. Overfilling a Penny with Droplets
A domed bubble of water mounds above the rim without spilling.
Type: ______________
Reason: ____________________
C. Towel Dipped in Water
Water creeps upward through the dry cotton fibers against gravity.
Type: ______________
Reason: ____________________
Properties of Water Guided Practice • Biology Curriculum Page 1 of 2
Water Powers Worksheet
Part II: Solutions & Biological Systems
Student Name:
3
The Universal Solvent: Solutes & Solvents
Memory Trick: Solute dissolves in Solvent
Solute Substance that gets dissolved (smaller amount)
e.g., Table Salt (NaCl)
Solvent Liquid that does the dissolving (larger amount)
e.g., Liquid Water (H2O)
=
Aqueous Solution Evenly mixed liquid blend
e.g., Saline Solution (Saltwater)
How Polarity Powers Dissolving: Water's negative oxygen pole (δ−) attracts positive ions (like Na+), while its positive hydrogen poles (δ+) attract negative ions (like Cl−). Water wedges between solute particles, surrounding each ion with a protective hydration shell.
*Nonpolar substances (fats, oils) have no charges for water to grab onto, so water molecules stick to each other instead.
Na+ Solute (Na+) surrounded by Solvent (H2O)
Examine each real-world mixture. Use the completed model in Row 1 to guide your answers:
| Mixture & Ingredients | Solute(s) [Dissolved] | Solvent [Liquid] | Polarity Explanation |
|---|
| Lemonade Drink Sugar crystals & lemon juice in water | Sugar & citric acid | Water (H2O) | Polar water attracts polar sugar molecules. |
| Ocean Seawater Dissolved sea salt (NaCl) in open sea | ___________________ | ___________________ | ___________________ |
| Blood Plasma Glucose & electrolytes in 92% liquid | ___________________ | ___________________ | ___________________ |
4
Biological Phenomenon: The Redwood Tree Paradox
Coastal redwoods grow over 350 feet tall without a mechanical pump, transporting water from soil to crown against gravity.
Water evaporates from leaf stomata (transpiration), pulling the unbroken column of water in microscopic xylem vessels.
Xylem Column
Question 1: How do cohesion and hydrogen bonding keep the continuous chain of water molecules from breaking as it is pulled upward?
Question 2: How does adhesion between water and xylem cell walls prevent the water column from sliding back down due to gravity?
5
Synthesis: Connect All Five Terms
Write a concise 2–3 sentence scientific explanation connecting all 5 terms: polarity, cohesion, adhesion, solute, and solvent to explain how water dissolves and transports nutrients through living plants.
Properties of Water Guided Practice • Biology Curriculum Page 2 of 2
