It looks like you've uploaded an image of a science worksheet titled
"Investigation: The Properties of Water". Based on the visible content, here's a breakdown and explanation of the activity and how to answer the questions.
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🔬 Overview of the Activity
The worksheet is designed to help students explore
the properties of water, specifically focusing on:
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Cohesion (water molecules sticking to each other)
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Adhesion (water sticking to other surfaces)
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Surface tension
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Capillary action
These are all due to
hydrogen bonding between water molecules.
The activity involves two parts:
1.
Penny and Water Experiment: See how many drops of water can fit on a penny before spilling.
2.
Soapy Water Comparison: Repeat the experiment with soapy water.
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🧪 Station 1: Pennies and Water
#### Materials:
- Penny
- Eye dropper
- Tap water
- Soapy water
#### Procedure:
1. Use a dropper to add drops of
tap water onto a clean penny until it overflows.
2. Count how many drops fit.
3. Repeat with
soapy water.
4. Record the number of drops in the table.
| Data | Tap Water | Soapy Water |
|------|-----------|-------------|
| Number of Drops | [e.g., 20] | [e.g., 10] |
> *(Note: Actual numbers will vary, but tap water usually holds more drops than soapy water.)*
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✔ Question 1: What property of water is demonstrated by this activity?
Answer:
This activity demonstrates
surface tension.
#### 💡 Explanation:
- Surface tension is the
"skin" that forms on the surface of water due to
cohesive forces between water molecules.
- Water molecules at the surface are pulled inward by neighboring molecules, creating a strong surface layer.
- This allows water to form a dome on the penny without spilling immediately.
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Hydrogen bonds between water molecules are responsible for this high surface tension.
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✔ Question 2: Explain why you had different results for the soapy water.
Answer:
The soapy water held fewer drops because
soap reduces surface tension.
#### 💡 Explanation:
- Soap molecules have
hydrophilic (water-loving) heads and
hydrophobic (water-repelling) tails.
- When soap is added to water, these molecules disrupt hydrogen bonds between water molecules.
- This
weakens cohesion and
lowers surface tension.
- As a result, the water cannot form a stable dome and spills more easily—so fewer drops fit on the penny.
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🌟 Summary of Key Concepts:
| Concept | Description |
|--------|-------------|
|
Cohesion | Water molecules stick to each other due to hydrogen bonds. |
|
Adhesion | Water sticks to other surfaces (e.g., glass or skin). |
|
Surface Tension | Result of cohesion; allows water to resist external forces. |
|
Effect of Soap | Breaks hydrogen bonds → lowers surface tension → weakens cohesion. |
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📝 Final Answers:
1. The property demonstrated is
surface tension, caused by the cohesive forces between water molecules due to hydrogen bonding.
2. Soapy water has fewer drops because
soap breaks hydrogen bonds, reducing surface tension and weakening the water’s ability to hold together in a dome shape.
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Let me know if you'd like a printable version of the answers or a diagram to go with it!
Parent Tip: Review the logic above to help your child master the concept of water properties worksheet.
