Dwg: Article written and Venn diagram created.

2025-11-12T23:08:26Z

Article written and Venn diagram created.

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== Comparison Article ==
In physics and chemistry, '''adhesion''' and '''cohesion''' are attractive forces between molecules that are responsible for several observable phenomena.<ref name="ref1" /><ref name="ref2" /> Adhesion is the force of attraction between molecules of different substances.<ref name="ref3" /> Cohesion is the force of attraction between molecules of the same substance.<ref name="ref3" /> These forces are present in solids, liquids, and gases, but are most commonly observed in the behavior of liquids.<ref name="ref4" /> The balance between adhesion and cohesion determines how a liquid interacts with a solid surface.<ref name="ref5" />

For example, when water is placed on a clean glass surface, the adhesive forces between the water molecules and the glass are stronger than the cohesive forces among the water molecules. This causes the water to spread out. Conversely, if water is placed on a waxy surface, the cohesive forces within the water are stronger than the adhesive forces between the water and the wax, causing the water to form beads or droplets.<ref name="ref5" />

=== Comparison Table ===
{| class="wikitable"
|-
! Category !! Adhesion !! Cohesion
|-
| '''Definition''' || Attraction between molecules of '''different''' substances.<ref name="ref1" /> || Attraction between molecules of the '''same''' substance.<ref name="ref1" />
|-
| '''Interacting Particles''' || Unlike molecules or surfaces (e.g., water and glass). || Like molecules (e.g., two water molecules).
|-
| '''Underlying Forces''' || Primarily electrostatic or mechanical forces between different substances. || Primarily hydrogen bonds and van der Waals forces within a single substance.
|-
| '''Common Examples''' || Dewdrops clinging to a leaf; paint sticking to a wall;<ref name="ref1" /> medical tape adhering to skin.<ref name="ref1" /> || Water forming droplets;<ref name="ref5" /> insects walking on water; mercury forming beads.
|-
| '''Resulting Phenomena''' || Causes capillary action, wetting of surfaces, and the formation of a concave meniscus. || Causes surface tension and the formation of a convex meniscus (as with mercury).<ref name="ref3" />
|}

[[File:Venn_diagram_Differences_between_Adhesion_versus_Cohesion_comparison.png|thumb|center|800px|alt=Venn diagram for Differences between Adhesion and Cohesion|Venn diagram comparing Differences between Adhesion and Cohesion]]

=== Surface Tension ===
Cohesion is responsible for surface tension, which is the tendency of a liquid's surface to resist rupture when under stress. Molecules within the bulk of a liquid are pulled equally in all directions by neighboring molecules. However, molecules at the surface experience a net inward pull from the molecules below them because there are fewer molecules above the surface. This inward force minimizes the surface area, causing the surface to behave like a stretched elastic sheet. The high surface tension of water, caused by strong hydrogen bonds between its molecules, allows some insects, such as the water strider, to stay afloat on its surface.<ref name="ref4" />

=== Capillary Action ===
Capillary action is the movement of a liquid through narrow spaces, even against gravity. This phenomenon occurs because of a combination of adhesion and cohesion. In a thin tube, such as the xylem in a plant stem, the adhesion between the water and the tube's walls pulls the water upward.<ref name="ref1" /> Cohesion ensures that the water molecules below are pulled up along with them.<ref name="ref1" /><ref name="ref4" /> The relative strengths of the adhesive and cohesive forces determine the shape of the liquid's surface in a tube, known as the meniscus. For water in a glass tube, strong adhesion creates a concave meniscus, while mercury's strong cohesion results in a convex meniscus.<ref name="ref3" />

== References ==
<references>
<ref name="ref1">[https://www.geeksforgeeks.org/physics/adhesion-and-cohesion/ "geeksforgeeks.org"]. Retrieved November 12, 2025.</ref>
<ref name="ref2">[https://phys.libretexts.org/Bookshelves/University_Physics/Physics_(Boundless)/10%3A_Fluids/10.4%3A_Cohesion_and_Adhesion "libretexts.org"]. Retrieved November 12, 2025.</ref>
<ref name="ref3">[https://www.ebsco.com/research-starters/physics/cohesion-chemistry "ebsco.com"]. Retrieved November 12, 2025.</ref>
<ref name="ref4">[https://byjus.com/chemistry/cohesive/ "byjus.com"]. Retrieved November 12, 2025.</ref>
<ref name="ref5">[https://www.biolinscientific.com/blog/understanding-cohesion-and-adhesion-the-forces-behind-everyday-phenomena "biolinscientific.com"]. Retrieved November 12, 2025.</ref>
</references>

[[Category:Comparisons]]

Differences between Adhesion and Cohesion - Revision history

Dwg: Article written and Venn diagram created.