Properties of Water and Cohesion

Mrs. Henderson discusses the properties of water, focusing on cohesion and surface tension. She explains how hydrogen bonds form between water molecules, leading to cohesion, which is demonstrated using wax paper and water droplets. The video also covers surface tension, illustrated through a mason jar experiment, showing how water can stay in the jar due to cohesive forces. The session concludes with a preview of the next week's topic on macromolecules.

What is the primary reason water molecules can form hydrogen bonds?

• Water molecules are hydrophobic.

• Water molecules are non-polar.

• Water molecules have polar covalent bonds.

• Water molecules have a high density.

What term describes the ability of water molecules to stick to each other?

• Adhesion

• Osmosis

• Cohesion

• Diffusion

Why do water droplets form spheres on a non-polar surface like wax paper?

• Due to evaporation

• Because of cohesion

• Due to adhesion

• Because of gravity

What happens when two water droplets on wax paper come close to each other?

• They flatten out.

• They repel each other.

• They merge into a larger droplet.

• They evaporate.

What property of water allows insects to walk on its surface?

• Buoyancy

• Density

• Surface tension

• Viscosity

In the mason jar experiment, what keeps the water from spilling out when the card is removed?

• Magnetic force

• Surface tension

• Gravity

• Air pressure

What happens if the surface tension of water is broken?

• The water remains in place.

• The water freezes.

• The water evaporates.

• The water spills out.

Which of the following is NOT a result of water's cohesive properties?

• Formation of water droplets

• Water's ability to dissolve salt

• Water's high boiling point

• Surface tension

What is the main topic of the next week's lesson as mentioned in the conclusion?

• Macromolecules

• Cellular respiration

• Photosynthesis

• Genetics

What is the significance of cohesion in biological systems?

• It prevents water from freezing.

• It decreases the density of water.

• It increases the temperature of water.

• It helps in the transport of nutrients in plants.