Properties of Water Assessment

How is cohesion related to surface tension?

• The water molecules are attracted to objects on the surface of the water.

• It invites lightweight insects to “walk” across to continue the water cycle through living organisms.

• The water molecules stick extra tight to the molecules around and below them creating an elastic “skin.”

Which property of water makes molecules of different substances, like water and a spider web, stick together?

• adhesion

• cohesion

• surface tension

Which property of water is responsible for the meniscus curve in a glass?

• adhesion

• cohesion

• surface tension

Which property of water allows water to resist outside forces?

• adhesion

• cohesion

• surface tension

A paper clip can float on the surface of water due to surface tension. What would happen if you added soap to the water, and why?

• The paper clip would sink because soap decreases surface tension.

• The paper clip would sink because the soap increases surface tension.

• The paper clip would float because the soap decreases surface tension.

Why do water droplets form round shapes on a smooth surface?

• adhesion between the surface and water

• cohesion between the water molecules

• gravity pulling them down

Tags

NGSS.MS-PS2-5

What two properties of water cause a small crater shape to form when rain falls onto a pond? Select ALL that apply.

• ahesion

• cohesion

• surface tension

Which situations model examples of adhesion? Select ALL that apply.

• water spreading out on a leaf

• water molecules sticking to each other

• water climbing up the inside of a straw

Students are observing the interaction between living organisms, like water striders, and the nonliving parts of an ecosystem. The water strider’s ability to “walk” on water helps it avoid being eaten. The students know that it is water’s properties that allows this. They made the following statements.

Chris: It doesn’t sink because of water’s adhesive properties.

Maria: It doesn’t sink because of water’s cohesive properties.

Which student has an accurate statement?

• Maria because cohesion means that the water molecules stick to each other creating surface tension.

• Chris because adhesion means that the water molecules stick to the water strider and keep it floating.

• Maria because cohesion means that the water molecules stick to the water strider and keep it floating.

Students are observing the interaction between living organisms, like water striders, and the nonliving parts of an ecosystem. The water strider’s ability to “walk” on water helps it avoid being eaten. The students know that it is water’s properties that allows this. They made the following statements.

Chris: It doesn’t sink because of water’s adhesive properties.

Maria: It doesn’t sink because of water’s cohesive properties.

Which other student makes a correct statement?

• A heavier insect may break the surface, even with cohesion.

• The surface of the water cannot be broken because of cohesion.

• The surface of the water cannot be broken because of adhesion.

Tags

NGSS.MS-PS1-2