Chapter 5, Lesson 2 Multimedia
Water's Surface Tension
- The paper clip is on the water but is not floating like a boat which is less dense than water.
- The paper clip is more dense than water but can rest on the surface of the water because of the water's surface tension.
Water Strider and Molecules
- Evidence of water's surface tension can be seen where the water strider's legs dent but do not break through the water's surface.
- The attraction of polar water molecules to each other helps create water's strong surface tension.
Why Water Beads
- The water molecules beneath the surface are pulled in all directions.
- The molecules at the surface are pulled together and in.
- This creates a tighter arrangement of molecules at the surface and the round shape of a drop of water.
Water and Alcohol
- Alcohol has one O–H bond which is polar but a large portion of the molecule is made up of C–H bonds which are nonpolar.
- Alcohol molecules do not attract each other as strongly as water molecules and have a weaker surface tension.
Water and Detergent
Please click on the image above to see a larger version.
- The charged end of a detergent molecule attracts water molecules at the surface in an outward direction.
- This disrupts the way the molecules normally attract at the surface and weakens the surface tension, causing the drop to collapse.
Water on Paper Towel
- Paper is made from cellulose which is made of glucose molecules bonded together.
- Glucose has many O–H bonds which are polar.
- Polar water molecules are attracted to the polar cellulose and cling to it.
- Lesson 1: Water is a Polar Molecule
- Lesson 2: Surface Tension
- Lesson 3: Why Does Water Dissolve Salt?
- Lesson 4: Why Does Water Dissolve Sugar?
- Lesson 5: Using Dissolving to Identify an Unknown
- Lesson 6: Does Temperature Affect Dissolving?
- Lesson 7: Can Liquids Dissolve in Water?
- Lesson 8: Can Gases Dissolve in Water?
- Lesson 9: Temperature Changes Dissolving
- Lesson 1: What is a Chemical Reaction?
- Lesson 2: Controlling the Amount of Products in a Chemical Reaction
- Lesson 3: Forming a Precipitate
- Lesson 4: Temperature and the Rate of a Chemical Reaction
- Lesson 5: A Catalyst and the Rate of Reaction
- Lesson 7: Energy Changes in Chemical Reactions
- Lesson 8: pH and Color Change
- Lesson 9: Neutralizing Acids and Bases
- Lesson 10: Carbon Dioxide Can Make a Solution Acidic