Allen pours water into a graduated cylinder. He notices that the surface of the water is curved, as shown below.

Graduated cylinder showing curved surface of water where the sides of the water are higher than the center

Which of the following identifies this phenomenon and explains how it is formed?

Choose 1

(Choice A)

The curved surface is a convex meniscus which has formed because of capillary action.

(Choice B)

The curved surface is a convex meniscus which has formed because of surface tension.

(Choice C)

The curved surface is a concave meniscus which has formed because of surface tension.

(Choice D)

The curved surface is a concave meniscus which has formed because of capillary action.

When water is added to a graduated cylinder, having a surface where the sides of the water look higher than the center means that the curved surface is a concave meniscus which has formed because of surface tension (Choice C).

Explanation:

A meniscus is simply the curvature that the surface of a liquid acquires when it is in a container, such as a graduated cylinder. It is concave when there is attraction between molecules -water and glass- or it can be convex when both surfaces are repelled.

Water is a polar molecule, with the capacity to adhere to the surfaces it comes into contact with. This characteristic causes it to form a concave meniscus, as the outermost molecules adhere to the glass surface, while the surface tension of the water attracts the molecules from the centre downwards, causing the concavity.

Learn more:

Measuring with a graduated cylinder link

answer; i believe the correct answer is (replication is not conservative);

step 1: nitrogen fixation- conversion of atmospheric no₂ into forms useful to plants by lightning, bacteria, and cyanobacteria.

step 2: nitrification-process of converting ammonia to nitrite or nitrate.

step 3: assimilation-plant roots absorb new form of nitrogen.

step 4: ammonification-conversion of organic nitrogen to ammonia by bacteria involved in decomposition.

step 5: denitrification-bacteria turns the decomposed matter back into n₂o, which is released into atmosphere; repeat cycle.