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Is Water Sticky?

Short answer: Water molecules attract one another through hydrogen bonds. At the surface, molecules have neighbors only below and beside them, so they're pulled inward, and the surface behaves like a stretched film.

That's surface tension, and water's is high for a liquid, about 72 millinewtons per meter at room temperature. Attraction between like molecules is called cohesion; attraction to other surfaces, like glass or a plant's xylem walls, is adhesion. Together they drive capillary action. Surface tension shapes drops, lets some insects stand on water and dominates fluid behavior in microgravity, where water forms floating spheres. The footage shows water beading on a coin and drops on surfaces.

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In collections:Everyday Physics

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What should you know about Is Water Sticky??

Quick facts. Each one stands alone and has a stable ID you can cite.

  1. Surface tension comes from water molecules pulling on each other.

    DD-296-F01 · Write-up · Exhibit A (Hydrogen bonds)

  2. Adhesion is attraction to other surfaces.

    DD-296-F02 · Write-up · Exhibit C (Cohesion vs. adhesion)

Video transcript: Is Water Sticky?: A Coin Can Hold a Dome of Water Above Its Edge

DID YOU KNOW? Surface tension in water is a result of its cohesive properties where water molecules strongly adhere to each other due to hydrogen bonding. This cohesion creates a "skin" on the water's surface that is resistant to external forces. This adhesive force is crucial in many natural processes including the formation of water droplets and the movement of water through plants. In technological applications it affects how liquids behave in different environments such as in microgravity or on hydrophobic surfaces. NOW YOU KNOW!

Burned-in captions, read frame by frame (see transcript.md) · 24.5s Reel ·

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Is Water Sticky?: A Coin Can Hold a Dome of Water Above Its Edge Instagram Reel · · 24.5s

The write-up

A coin can hold a dome of water above its edge. Cohesion holds water to water; adhesion holds it to other things.

  1. Exhibit A

    Hydrogen bonds

    Water molecules attract each other through hydrogen bonds.

  2. Exhibit B

    A stretched film

    Surface molecules are pulled inward, so the surface acts like a film.

  3. Exhibit C

    Cohesion vs. adhesion

    Cohesion is water-to-water attraction; adhesion is attraction to other surfaces.

  4. Exhibit D

    Capillary action

    Cohesion and adhesion together drive capillary action.

  5. Exhibit E

    In microgravity

    Without gravity, surface tension pulls water into spheres.

Questions people ask about Is Water Sticky?

What attracts water molecules to each other?

That's the root of surface tension.

Source: Write-up · Exhibit A (Hydrogen bonds) · Wikipedia: Surface tension

Why does the surface act like a film?

They lack neighbors above.

Source: Write-up · Exhibit B (A stretched film) · Wikipedia: Surface tension

What's attraction to other surfaces called?

Cohesion is water-to-water.

Source: Write-up · Exhibit C (Cohesion vs. adhesion) · Wikipedia: Surface tension

What do cohesion and adhesion drive together?

It lifts water in narrow tubes.

Source: Write-up · Exhibit D (Capillary action) · Wikipedia: Surface tension

What shape does water take in microgravity?

Surface tension pulls it round.

Source: Write-up · Exhibit E (In microgravity) · Wikipedia: Surface tension

Test Your Knowledge

All quizzes →

5 questions, all from this case file. Answers are revealed instantly.

  1. What attracts water molecules to each other?

    1. Hydrogen bonds
    2. Magnetism
    3. Gravity
    4. Static from air
    Show the answer

    Answer: A. Hydrogen bonds That's the root of surface tension. Source: Write-up · Exhibit A (Hydrogen bonds) · Wikipedia: Surface tension

  2. Why does the surface act like a film?

    1. Surface molecules are pulled inward
    2. Air pushes down
    3. Dust forms a layer
    4. Light hardens it
    Show the answer

    Answer: A. Surface molecules are pulled inward They lack neighbors above. Source: Write-up · Exhibit B (A stretched film) · Wikipedia: Surface tension

  3. What's attraction to other surfaces called?

    1. Adhesion
    2. Cohesion
    3. Friction
    4. Inertia
    Show the answer

    Answer: A. Adhesion Cohesion is water-to-water. Source: Write-up · Exhibit C (Cohesion vs. adhesion) · Wikipedia: Surface tension

  4. What do cohesion and adhesion drive together?

    1. Capillary action
    2. Evaporation
    3. Freezing
    4. Boiling
    Show the answer

    Answer: A. Capillary action It lifts water in narrow tubes. Source: Write-up · Exhibit D (Capillary action) · Wikipedia: Surface tension

  5. What shape does water take in microgravity?

    1. Spheres
    2. Cubes
    3. Flat sheets
    4. Rings
    Show the answer

    Answer: A. Spheres Surface tension pulls it round. Source: Write-up · Exhibit E (In microgravity) · Wikipedia: Surface tension

Cite this case file

Easterling, Marcus. "Is Water Sticky?." The Detail Department (DetailEnjoyer), case file DD-296, last updated Aug 11, 2024. https://detailenjoyer.com/case/is-water-sticky/

Permalink: https://detailenjoyer.com/case/is-water-sticky/ · Last updated

Markdown version

Cite a single fact by its ID, for example DD-296-F01 → https://detailenjoyer.com/case/is-water-sticky/#DD-296-F01

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