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Guilherme Mazui

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What is the Difference Between Cohesion and Surface Tension?

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The main difference between cohesion and surface tension lies in the forces they describe and the phenomena they cause. Here is a summary of their differences:

  • Cohesion: Cohesive forces are attractive forces between molecules of the same type. These forces cause the molecules to aggregate, forming a continuous substance. Cohesion is responsible for the formation of droplets, bubbles, and other structures in liquids.
  • Surface Tension: Surface tension is a property of liquids that arises due to cohesive forces between identical liquid molecules. It is the elasticity of the surface of a liquid, causing the surface to contract to the smallest possible area. This phenomenon is observed when droplets of water or other liquids form on a surface, creating a "surface film" that makes it difficult for objects to penetrate the liquid.

In summary, cohesion refers to the attraction between molecules of the same substance, while surface tension is a result of cohesive forces at the surface of a liquid, causing it to contract and exhibit elastic properties.

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  • What is the Difference Between Cohesion and Surface Tension?
  • Comparative Table: Cohesion vs Surface Tension

    • Comparative Table: Cohesion vs Surface Tension

    Cohesion and surface tension are related phenomena in liquids, but they differ in their specific aspects. Here is a table highlighting the differences between cohesion and surface tension:

    Feature Cohesion Surface Tension
    Definition Cohesion refers to the attraction between molecules of the same substance. Surface tension is the result of cohesive forces at the surface of a liquid, causing the surface to contract to the smallest possible area.
    Cause Cohesive forces, which can be hydrogen bonding in the case of water. Molecules on the surface are pulled inward by cohesive forces, reducing the surface area.
    Effect on Liquids Cohesive forces hold liquid molecules together, making it difficult to separate them. Surface tension causes the tendency of a liquid's surface to resist rupture when placed under stress.
    Examples Water droplets, meniscus formation in capillaries. Water droplets on a smooth surface, dew drops on a spider web.

    In summary, cohesion refers to the attraction between molecules of the same substance, while surface tension is a result of cohesive forces at the surface of a liquid, causing the surface to contract to the smallest possible area.

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    Guilherme Mazui

    Guilherme Mazui is graduated in journalism from the Federal University of Minas Gerais (UFMG) and a master's degree in Communication from the University of São Paulo (USP). In addition, he has experience in advertising writing and has worked as a content editor in several companies.