Which of the following should be classified as a mixture? water air iron helium

air

Explanation:

A mixture is a combination of two or more substances. When substances mix together it results in a change in their physical as well as chemical form. A mixture exhibit a chemical and physical form different from the constituent substances.

An air is a mixture of gases. It forms a part of the atmosphere. Air may contain gases like carbon dioxide, water vapors, nitrogen, oxygen, and others.

both adhesion and cohesion are attractions.

they are different in that adhesion is the force of attraction between the molecules of two different substances, whereas cohesion is the force of attraction between molecules of the same substance.

possible examples include capillary action, in which the adhesion between water and glass causes the water to rise in a narrow tube against the force of gravity.

because of hydrogen bonding, water is extremely cohesive.

this causes molecules on the surface of water to be drawn inward, which is why drops of water form beads on smooth surfaces.

hope this .