# Difference Between Cohesion and Adhesion Author: Nex Virox Team (Editorial Team) Reviewed by: Varshal Nirbhavane Published: 2026-09-05 Last updated: 2026-09-05 Canonical: https://nexvirox.com/difference-between/difference-between-cohesion-and-adhesion/ **Quick answer:** The main difference between Cohesion and Adhesion is that cohesion is the attraction between molecules of the same substance, while adhesion is the attraction between molecules of different substances. Cohesion is the internal force holding a material together, while Adhesion is the force that makes different materials stick to each other.

Difference Between Cohesion and Adhesion: Comparison Table

Aspect	Cohesion	Adhesion
Definition	Attraction between molecules of the same substance, holding them together.	Attraction between molecules of different substances, binding them at a surface.
Purpose	Maintains internal integrity and resistance to separation within a material.	Enables bonding between two distinct materials or a material and a surface.
Core Mechanism	Intermolecular forces like hydrogen bonds and van der Waals forces act between identical molecules.	Intermolecular forces act between unlike molecules, often involving polar or ionic interactions.
Force Type	Intermolecular forces operate within a single material's molecular structure.	Surface forces operate across the interface separating two different materials.
Molecular Similarity	Molecules are identical in chemical composition and polarity.	Molecules differ chemically, yet complementary polarities or charges enable attraction.
Structural Role	Provides tensile strength and shape stability to a bulk material.	Provides interfacial bonding strength between layers, coatings, or components.
Water Example	Water molecules attract each other, forming droplets and surface tension.	Water molecules attract glass or plant cell walls, causing wetting and capillary rise.
Surface Tension	Creates surface tension by pulling surface molecules inward toward the bulk.	Reduces surface tension when a liquid spreads across a solid surface.
Meniscus Effect	Water's cohesive forces produce a convex meniscus in narrow glass tubes.	Water's adhesive forces to glass produce a concave meniscus at tube walls.
Capillary Action	Cohesion pulls water molecules upward in a continuous chain within the tube.	Adhesion pulls water molecules to tube walls, enabling upward movement against gravity.
Mercury Behaviour	Strong cohesive forces make mercury form tight spherical droplets.	Weak adhesive forces to glass prevent mercury from wetting or spreading.
Glue Function	Cohesive strength holds glue molecules together internally.	Adhesive strength binds glue to the surfaces being joined.
Failure Mode	Cohesive failure occurs when a material splits internally, leaving residue on both surfaces.	Adhesive failure occurs at the interface, cleanly separating the bonded materials.
Bond Strength	Determines a material's resistance to internal cracking or tearing.	Determines a joint's resistance to separation at the contact interface.
Temperature Effect	Rising temperature weakens cohesive forces, softening or melting the material.	Rising temperature can degrade adhesive bonds, especially in thermoplastic adhesives.
Moisture Impact	Water can disrupt cohesive bonds, causing swelling or dissolution of materials.	Moisture can weaken adhesion by displacing adhesive molecules from the surface.
Surface Roughness	Internal cohesion is largely unaffected by surface texture.	Rougher surfaces increase adhesion area and mechanical interlocking.
Surface Cleanliness	Internal cohesive forces do not depend on surface contamination.	Contaminants like oil or dust block adhesion by preventing molecular contact.
Measurement Method	Measured via tensile or shear tests on a material's bulk specimen.	Measured via peel, lap-shear, or pull-off tests on bonded assemblies.
Units	Expressed as stress in megapascals (MPa) or pounds per square inch (psi).	Expressed as force per width in newtons per meter (N/m) or pounds per inch (pli).
Scalability	Scales with material volume; thicker sections generally show higher total strength.	Scales with contact area; larger bonded surfaces carry proportionally higher loads.
Maintenance	Requires monitoring for internal cracks, voids, or material fatigue.	Requires inspection of bond lines for peeling, delamination, or edge lifting.
Safety Factor	Cohesive failure often signals material degradation before sudden collapse.	Adhesive failure can cause abrupt joint separation without prior visible warning.
Compatibility	Occurs between any identical molecules regardless of external surface chemistry.	Requires chemical compatibility between adhesive and substrate for durable bonding.
Reversibility	Cohesive bonds reform readily when melted or dissolved and re-solidified.	Adhesive bonds are often irreversible, leaving residue or damaging surfaces on removal.
Common Example	Water droplets beading on a waxed car hood demonstrate strong cohesion.	Water spreading on clean glass demonstrates strong adhesion to the surface.
Industrial Use	Used in polymer extrusion, fibre spinning, and casting to maintain part integrity.	Used in paints, coatings, laminates, and structural bonding in aerospace and automotive.
Biological Role	Enables water transport in plants via a continuous cohesive water column.	Enables water uptake from soil into root hairs through surface attraction.
Typical Users	Material scientists, polymer engineers, and metallurgists study internal strength.	Adhesive formulators, surface chemists, and bonding engineers design interfaces.
Best-Fit Scenario	Choose cohesion when selecting a material that must resist internal fracture under load.	Choose adhesion when joining dissimilar materials or bonding coatings to substrates.

What Is Cohesion?

Cohesion is the attraction between molecules of the same substance. It holds a material together internally, creating surface tension and structural integrity. Cohesion exists because intermolecular forces, such as hydrogen bonds, pull identical molecules toward one another.

Definition of Cohesion

Cohesion is the intermolecular force that binds identical molecules to each other. This attraction results from shared chemical properties, including hydrogen bonding, van der Waals forces, or metallic bonds. Cohesion determines a substance's resistance to separation, influencing properties like viscosity, surface tension, and tensile strength.

Key Characteristics of Cohesion

Characteristic	What It Means in Practice
Same-molecule attraction	Cohesion only occurs between identical molecules, never between different substances.
Hydrogen bonding	Water molecules form strong hydrogen bonds, giving liquid water high internal stickiness.
Surface tension creation	Cohesive forces pull surface molecules inward, forming a stretched elastic-like film.
Resistance to separation	Cohesive materials resist being pulled apart, requiring external force to break bonds.
Droplet formation	Cohesion causes liquids to bead into spherical droplets, minimising exposed surface area.
Density dependence	Cohesive strength varies with molecular size, shape, and the number of bonding sites.
Temperature sensitivity	Rising temperature adds kinetic energy, weakening cohesive bonds and reducing surface tension.
Capillary contribution	Cohesion works with adhesion to pull liquids up narrow tubes against gravity.
State-dependent strength	Solids show strong cohesion; liquids moderate; gases have negligible cohesive forces.
Internal pressure source	Cohesive forces create internal pressure within liquids, influencing boiling and freezing points.

Common Examples of Cohesion

Water droplets on a leaf – Hydrogen bonds pull water molecules into a spherical bead shape.
Mercury pooling – Strong metallic cohesion makes mercury form near-perfect spheres on flat surfaces.
Raindrops falling – Cohesion keeps thousands of water molecules together as a single falling drop.
Water strider on ponds – Surface tension from cohesion supports the insect's weight without breaking the film.
Waxed car beading – Cohesion dominates over adhesion, forcing water into tight round beads.
Steel structural beams – Metallic bonds provide strong cohesion, resisting bending and fracture under load.
Glue curing process – Cohesion within the dried adhesive gives the bond its internal strength.
Liquid mercury in thermometer – Cohesion keeps the mercury column intact and unbroken as temperature changes.
Salt crystal formation – Ionic cohesive forces lock ions into a rigid, repeating lattice structure.
Spider web silk – Protein chains held by cohesive forces give silk its high tensile strength.

Advantages and Limitations of Cohesion

Advantages	Limitations
Enables surface tension, allowing small insects to walk on liquid surfaces.	Excessive cohesion prevents liquids from spreading, hindering wetting and coating processes.
Provides structural integrity in solids, resisting fracture and deformation under stress.	Strong cohesion in soil causes cracking and poor water infiltration in dry conditions.
Allows water transport in plants via the transpiration stream, pulling water upward.	Cohesion alone cannot overcome gravity in tall trees; it requires adhesion and evaporation pull.
Keeps liquid columns intact in pipettes and syringes for accurate measurement.	High cohesion makes viscous liquids difficult to pump, increasing energy costs in industry.
Creates stable droplets for spray applications like pesticides and inks.	Droplet formation prevents even coverage, causing streaking in paints and coatings.
Enables formation of strong adhesive joints once the adhesive itself cures.	Cohesive failure within the adhesive layer causes joints to fail even with perfect surface prep.
Supports the water cycle by allowing rain to form as cohesive droplets.	Cohesion in clouds delays rainfall, leading to sudden heavy downpours instead of light drizzle.
Gives mercury its unique non-wetting property, useful in barometers.	Non-wetting behaviour makes mercury useless for cleaning or spreading applications.
Maintains the shape of liquid jets in fountains and inkjet printers.	Jet breakup from cohesion limits printing speed and resolution in inkjet technology.
Provides predictable melting and boiling points in pure substances.	Cohesion varies with impurities, making industrial processes harder to control precisely.

What Is Adhesion?

Adhesion is the attraction between molecules of two different substances, causing them to stick together. It exists because intermolecular forces, such as hydrogen bonds or van der Waals forces, pull dissimilar materials toward one another. This binding action underpins countless everyday processes, from painting walls to medical bandages.

Definition of Adhesion

Adhesion is the molecular force of attraction that holds two distinct materials together at their contacting surfaces. This phenomenon arises from intermolecular interactions, including hydrogen bonding, electrostatic forces, or mechanical interlocking. Unlike cohesion, which binds identical molecules, adhesion specifically describes the tendency of unlike substances to resist separation when placed in contact.

Key Characteristics of Adhesion

Characteristic	What It Means in Practice
Dissimilar materials	Requires two different substances, such as water and glass, to create a bonding interface.
Surface contact	Strength depends directly on how intimately the two surfaces touch each other.
Intermolecular forces	Relies on hydrogen bonds, van der Waals forces, or dipole interactions for attraction.
Surface energy	High-energy surfaces like metals bond more readily than low-energy plastics.
Wettability factor	Liquids must spread across a solid surface for effective adhesive contact to occur.
Mechanical interlocking	Rough surfaces physically anchor the adhesive, boosting bond strength significantly.
Temperature sensitive	Heat can weaken or strengthen bonds depending on the adhesive's chemical composition.
Reversible potential	Some adhesive bonds can be broken and reformed without permanent material damage.
Thin film nature	Adhesive layers are typically microscopic, measured in micrometers, not millimeters.
Failure modes	Breaks occur either at the interface, called adhesive failure, or within the adhesive itself.

Common Examples of Adhesion

Water on glass – hydrogen bonds pull water molecules to the silica surface, forming a thin film.
Painting walls – liquid paint adheres to drywall through mechanical anchoring and molecular attraction.
Medical bandages – adhesive polymers bond to skin via weak intermolecular forces that allow painless removal.
Postage stamps – the gum layer adheres to paper envelopes through hydrogen bonding once moistened.
Spider silk – the sticky droplets on webs use adhesion to trap flying insects mid-air.
Gecko feet – millions of microscopic setae create van der Waals adhesion on vertical surfaces.
Glue on wood – wood glue penetrates pores and hardens, creating a strong mechanical interlock.
Ink on paper – printer ink adheres to cellulose fibers through capillary action and absorption.
Duct tape – the rubber-based adhesive bonds to various surfaces via pressure-sensitive contact.
Concrete on steel – cement paste adheres to rebar, enabling reinforced structures to carry loads.

Advantages and Limitations of Adhesion

Advantages	Limitations
Enables joining of dissimilar materials that welding or fasteners cannot connect.	Bonds degrade rapidly under prolonged exposure to moisture or high humidity.
Distributes stress evenly across a joint, preventing localised pressure points.	Surface preparation is mandatory; dirt or grease drastically reduces bond strength.
Creates lightweight assemblies without adding bolts, rivets, or heavy hardware.	Temperature extremes cause adhesive embrittlement or softening, leading to premature failure.
Provides a continuous seal that blocks fluids, gases, and contaminants from passing.	Most adhesives require curing time, slowing down production and assembly processes.
Allows bonding of heat-sensitive components that welding would damage.	Predicting long-term durability is difficult because environmental aging is highly variable.
Reduces vibration and dampens noise between bonded panels and structures.	Disassembly is destructive; bonded parts rarely separate without damaging the substrate.
Works on irregular or curved geometries that mechanical fasteners cannot accommodate.	Solvent-based adhesives release volatile organic compounds that harm air quality.
Improves aesthetics by eliminating visible screw heads or weld marks on surfaces.	Strength drops sharply on low-energy plastics like polyethylene without specialised primers.
Resists galvanic corrosion by insulating dissimilar metals from direct contact.	Quality control is challenging because hidden voids or air pockets weaken the joint invisibly.
Enables automation in manufacturing, applying precise adhesive amounts rapidly.	Bond performance relies heavily on operator skill and consistent application technique.

Similarities Between Cohesion and Adhesion

Shared Aspect	How Cohesion and Adhesion Are Alike
Molecular Forces	Both cohesion and adhesion arise from intermolecular forces acting between molecules at a material interface.
Physical Phenomenon	Cohesion and adhesion are both physical phenomena that govern how molecules interact without forming chemical bonds.
Surface Interaction	Both cohesion and adhesion depend on the surface energy and molecular arrangement of the materials involved.
Hydrogen Bonding	Cohesion and adhesion both frequently rely on hydrogen bonds as a primary source of attractive force.
Van Der Waals	Cohesion and adhesion both utilize van der Waals forces to hold molecules or surfaces together.
Liquid Behavior	Cohesion and adhesion both determine how liquids spread, bead, or climb on solid surfaces.
Capillary Action	Cohesion and adhesion both work together to enable capillary action in narrow tubes and porous materials.
Meniscus Shape	Cohesion and adhesion both influence whether a liquid forms a concave or convex meniscus in a container.
Wetting Process	Cohesion and adhesion both control the wetting process when a liquid contacts a solid surface.
Contact Angle	Cohesion and adhesion both determine the contact angle measured at the liquid-solid boundary.
Water Transport	Cohesion and adhesion both enable water transport in plants through xylem vessels against gravity.
Biological Systems	Cohesion and adhesion both support essential biological functions like blood flow and cell attachment.
Material Science	Cohesion and adhesion both are fundamental concepts used in material science and surface engineering.
Adhesive Products	Cohesion and adhesion both are required for adhesive tapes, glues, and sealants to function properly.
Coating Durability	Cohesion and adhesion both determine the durability and performance of paints and protective coatings.
Temperature Dependent	Cohesion and adhesion both weaken or strengthen with changes in temperature and thermal energy.
Pressure Affected	Cohesion and adhesion both respond to applied pressure, which can enhance molecular contact and bonding.
Surface Roughness	Cohesion and adhesion both are influenced by the roughness and texture of the interacting surfaces.
Measurable Quantities	Cohesion and adhesion both can be quantified through force measurements and surface tension tests.
Lab Testing	Cohesion and adhesion both are measured using similar laboratory techniques like contact angle goniometry.
Predictable Models	Cohesion and adhesion both follow predictable mathematical models based on molecular interaction theories.
Failure Modes	Cohesion and adhesion both exhibit failure modes that determine whether a bond breaks internally or at an interface.
Quality Control	Cohesion and adhesion both are critical quality control parameters in manufacturing and production processes.
Environmental Impact	Cohesion and adhesion both are affected by humidity, contaminants, and environmental exposure conditions.
Surface Cleaning	Cohesion and adhesion both require clean surfaces to achieve maximum bonding strength and reliability.
Cost Implications	Cohesion and adhesion both influence material costs and product performance in industrial applications.
Failure Risk	Cohesion and adhesion both carry failure risks that can lead to product defects or structural weaknesses.
Maintenance Needs	Cohesion and adhesion both require periodic inspection and maintenance in long-term infrastructure applications.
Long-Term Stability	Cohesion and adhesion both affect the long-term stability and lifespan of bonded or coated materials.
Practical Applications	Cohesion and adhesion both are essential for everyday technologies like inkjet printing and medical adhesives.

Cohesion or Adhesion: Which Should You Choose?

The deciding variable is whether you need a material to hold itself together or stick to a different surface. If your failure mode involves internal splitting or tearing, cohesion wins. If your failure mode involves parts separating at an interface, adhesion wins.

When to Use Cohesion

Choose Cohesion when you need a single material to resist internal fracture, such as in load-bearing concrete, welded joints, or structural plastics. It also fits when you are bonding identical materials or when surface contamination makes adhesion unreliable. Prioritize it for high-stress internal integrity.

When to Use Adhesion

Choose Adhesion when you must join two different materials, like paint on metal, tape on glass, or coatings on wood. It is essential when the interface is the weakest point or when surfaces are smooth and non-porous. Select it for sealing, laminating, or attaching layers.

Common Misconceptions About Cohesion and Adhesion

Common Myth The Reality

Cohesion and adhesion are the same force acting in different directions. Cohesion attracts molecules of the same substance to each other, while adhesion attracts molecules of two different substances.

Adhesion is always stronger than cohesion in every material. Cohesion dominates in mercury, causing it to bead up, while adhesion dominates in water on clean glass, causing spreading.

Cohesion only happens in liquids, never in solids or gases. Cohesion holds solid metal atoms together in a crystal lattice and also acts between gas molecules during condensation.

Adhesion requires a liquid to be present between two surfaces. Adhesion occurs between dry solids too, such as between two polished glass plates or gecko foot hairs and a wall.

Water molecules only experience adhesion, not cohesion. Water molecules experience both forces simultaneously, with cohesion between water molecules and adhesion to container walls.

Cohesion is caused by gravity pulling molecules downward. Cohesion results from intermolecular forces like hydrogen bonds and van der Waals forces, not from gravitational attraction.

Adhesion is just another word for friction between surfaces. Friction resists sliding motion, while adhesion is an attractive force that pulls different materials together at their interface.

If a liquid wets a surface, cohesion is stronger than adhesion. Wetting occurs when adhesion between liquid and surface exceeds cohesion within the liquid, causing the liquid to spread.

Cohesion and adhesion can be measured with a simple thermometer. Cohesion and adhesion are measured indirectly through contact angle, surface tension, or peel tests, not with temperature tools.

Mercury has high adhesion to glass because it is a metal. Mercury has weak adhesion to glass because its strong cohesive forces pull it into spherical droplets instead of spreading.

Adhesion only matters for glues and tapes, not for natural processes. Adhesion drives water transport in plant xylem, ink sticking to paper, and paint bonding to walls in everyday life.

Cohesion is a chemical bond like a covalent or ionic bond. Cohesion is a physical intermolecular attraction, not a chemical bond, so it does not form new molecules or compounds.

Water has no cohesion because it flows easily and pours quickly. Water has strong cohesion via hydrogen bonds, which is why it forms droplets and supports surface tension on a penny.

Adhesion between water and glass is weaker than water cohesion. Water adheres to clean glass more strongly than it coheres to itself, causing water to climb up the glass wall.

Cohesion keeps a paper towel dry when it touches water. Adhesion pulls water into paper towel fibers, while cohesion keeps the water column intact as it wicks upward.

Adhesion is a property of the liquid alone, not the surface. Adhesion depends on both materials, so water adheres strongly to glass but weakly to wax or Teflon surfaces.

Cohesion disappears when a liquid is heated to its boiling point. Cohesion weakens with heat but remains active until molecules completely separate into a gas at the boiling point.

Glue works by increasing cohesion between two pieces of wood. Glue works through adhesion to each wood surface, bridging the gap and bonding to both sides simultaneously.

Raindrops are round because of adhesion to air molecules. Raindrops are round because water cohesion pulls molecules into the lowest surface area shape, a sphere, not due to air.

Cohesion and adhesion are the same as surface tension and capillary action. Surface tension and capillary action are observable effects caused by cohesion and adhesion, not the forces themselves.

Adhesion is stronger in gases than in liquids because gases expand. Adhesion is negligible in gases because molecules are too far apart for intermolecular forces to act effectively.

Cohesion only occurs between identical atoms, not identical molecules. Cohesion occurs between identical molecules too, such as between water molecules or between ethanol molecules in a liquid.

Paint sticks to a wall because of cohesion inside the paint layer. Paint sticks to a wall because of adhesion between paint polymers and the wall surface, not because of internal paint cohesion.

Water beads on a car hood because adhesion is very strong. Water beads on a waxed car hood because weak adhesion lets cohesion pull water into tight spherical droplets.

Cohesion is a force that pushes molecules apart rather than pulling them together. Cohesion is an attractive force that pulls like molecules together, which is why liquids resist being separated or stretched.

Adhesion requires a chemical reaction to occur between two surfaces. Adhesion often relies on physical intermolecular forces like van der Waals interactions, requiring no chemical reaction at all.

Cohesion is stronger in oil than in water because oil is thicker. Water has stronger cohesion than oil due to hydrogen bonding, despite oil being more viscous and thicker in texture.

Adhesion causes water to form a dome on a penny, not cohesion. Cohesion holds the water dome together on a penny, while adhesion only anchors the bottom layer to the coin surface.

Cohesion and adhesion are only relevant in physics labs, not daily life. Cohesion and adhesion explain why ink writes, why rain beads, why plants drink, and why tape sticks in daily life.

Adhesion is the force that makes water droplets merge into one larger drop. Cohesion makes water droplets merge, while adhesion is the force that makes water stick to a finger or a leaf surface.

Conclusion
Difference Between Cohesion and Adhesion is attraction within one substance versus attraction between two different substances. Cohesion holds molecules together, creating surface tension and droplets. Adhesion binds dissimilar materials, enabling wetting and bonding. Choose cohesion for internal strength; choose adhesion for sticking surfaces together.
## FAQ ### What is the difference between cohesion and adhesion? Cohesion is the attraction between molecules of the same substance, while adhesion is the attraction between molecules of different substances, and both forces compete to determine how a liquid behaves on a surface. ### Is adhesion stronger than cohesion in water? No, cohesion is stronger than adhesion in bulk water because hydrogen bonds between water molecules pull them together, but adhesion can dominate at surfaces like glass where the attraction to the material exceeds the internal pull. ### Which is more important, cohesion or adhesion, for plant water transport? Adhesion is more important for the initial upward pull in plant stems because it lets water cling to xylem walls, but cohesion is equally critical as it keeps the water column unbroken under tension. ### Does adhesion cost more energy than cohesion in industrial processes? Yes, adhesion typically costs more energy in industrial processes because overcoming the bond between a liquid and a solid surface, such as in cleaning or coating removal, requires more work than separating identical liquid molecules. ### Is adhesion a safety risk in pipeline systems? Yes, adhesion is a safety risk in pipeline systems because residual liquid clinging to pipe walls can cause contamination, corrosion, or blockages over time, especially when the adhesive force exceeds the flow's shear stress. ### Is cohesion compatible with all surface types? No, cohesion is not compatible with all surface types because it only acts between molecules of the same substance, so its effect on a surface depends entirely on whether adhesion or external forces disrupt the internal attraction. ### What is the most common beginner mistake when studying cohesion and adhesion? The most common beginner mistake is assuming cohesion only applies to liquids, when in fact it also acts in solids and gases, and confusing it with adhesion whenever two different materials touch. ### Can cohesion and adhesion be used interchangeably in physics? No, cohesion and adhesion cannot be used interchangeably in physics because cohesion always refers to same-substance attraction, while adhesion always refers to different-substance attraction, and swapping them changes the meaning of any force analysis. ### How does adhesion affect the real-world use of glue on wet surfaces? Adhesion makes glue stick to wet surfaces poorly because water molecules preferentially adhere to the solid, forming a barrier that prevents the adhesive from contacting the surface and reducing the bond strength significantly. ### Can I switch from relying on cohesion to adhesion in a liquid sealant? Yes, you can switch from relying on cohesion to adhesion in a liquid sealant, but only by changing the surface chemistry or adding a primer, because the sealant must then bond to the substrate instead of just holding itself together.

Common Myth	The Reality
Cohesion and adhesion are the same force acting in different directions.	Cohesion attracts molecules of the same substance to each other, while adhesion attracts molecules of two different substances.
Adhesion is always stronger than cohesion in every material.	Cohesion dominates in mercury, causing it to bead up, while adhesion dominates in water on clean glass, causing spreading.
Cohesion only happens in liquids, never in solids or gases.	Cohesion holds solid metal atoms together in a crystal lattice and also acts between gas molecules during condensation.
Adhesion requires a liquid to be present between two surfaces.	Adhesion occurs between dry solids too, such as between two polished glass plates or gecko foot hairs and a wall.
Water molecules only experience adhesion, not cohesion.	Water molecules experience both forces simultaneously, with cohesion between water molecules and adhesion to container walls.
Cohesion is caused by gravity pulling molecules downward.	Cohesion results from intermolecular forces like hydrogen bonds and van der Waals forces, not from gravitational attraction.
Adhesion is just another word for friction between surfaces.	Friction resists sliding motion, while adhesion is an attractive force that pulls different materials together at their interface.
If a liquid wets a surface, cohesion is stronger than adhesion.	Wetting occurs when adhesion between liquid and surface exceeds cohesion within the liquid, causing the liquid to spread.
Cohesion and adhesion can be measured with a simple thermometer.	Cohesion and adhesion are measured indirectly through contact angle, surface tension, or peel tests, not with temperature tools.
Mercury has high adhesion to glass because it is a metal.	Mercury has weak adhesion to glass because its strong cohesive forces pull it into spherical droplets instead of spreading.
Adhesion only matters for glues and tapes, not for natural processes.	Adhesion drives water transport in plant xylem, ink sticking to paper, and paint bonding to walls in everyday life.
Cohesion is a chemical bond like a covalent or ionic bond.	Cohesion is a physical intermolecular attraction, not a chemical bond, so it does not form new molecules or compounds.
Water has no cohesion because it flows easily and pours quickly.	Water has strong cohesion via hydrogen bonds, which is why it forms droplets and supports surface tension on a penny.
Adhesion between water and glass is weaker than water cohesion.	Water adheres to clean glass more strongly than it coheres to itself, causing water to climb up the glass wall.
Cohesion keeps a paper towel dry when it touches water.	Adhesion pulls water into paper towel fibers, while cohesion keeps the water column intact as it wicks upward.
Adhesion is a property of the liquid alone, not the surface.	Adhesion depends on both materials, so water adheres strongly to glass but weakly to wax or Teflon surfaces.
Cohesion disappears when a liquid is heated to its boiling point.	Cohesion weakens with heat but remains active until molecules completely separate into a gas at the boiling point.
Glue works by increasing cohesion between two pieces of wood.	Glue works through adhesion to each wood surface, bridging the gap and bonding to both sides simultaneously.
Raindrops are round because of adhesion to air molecules.	Raindrops are round because water cohesion pulls molecules into the lowest surface area shape, a sphere, not due to air.
Cohesion and adhesion are the same as surface tension and capillary action.	Surface tension and capillary action are observable effects caused by cohesion and adhesion, not the forces themselves.
Adhesion is stronger in gases than in liquids because gases expand.	Adhesion is negligible in gases because molecules are too far apart for intermolecular forces to act effectively.
Cohesion only occurs between identical atoms, not identical molecules.	Cohesion occurs between identical molecules too, such as between water molecules or between ethanol molecules in a liquid.
Paint sticks to a wall because of cohesion inside the paint layer.	Paint sticks to a wall because of adhesion between paint polymers and the wall surface, not because of internal paint cohesion.
Water beads on a car hood because adhesion is very strong.	Water beads on a waxed car hood because weak adhesion lets cohesion pull water into tight spherical droplets.
Cohesion is a force that pushes molecules apart rather than pulling them together.	Cohesion is an attractive force that pulls like molecules together, which is why liquids resist being separated or stretched.
Adhesion requires a chemical reaction to occur between two surfaces.	Adhesion often relies on physical intermolecular forces like van der Waals interactions, requiring no chemical reaction at all.
Cohesion is stronger in oil than in water because oil is thicker.	Water has stronger cohesion than oil due to hydrogen bonding, despite oil being more viscous and thicker in texture.
Adhesion causes water to form a dome on a penny, not cohesion.	Cohesion holds the water dome together on a penny, while adhesion only anchors the bottom layer to the coin surface.
Cohesion and adhesion are only relevant in physics labs, not daily life.	Cohesion and adhesion explain why ink writes, why rain beads, why plants drink, and why tape sticks in daily life.
Adhesion is the force that makes water droplets merge into one larger drop.	Cohesion makes water droplets merge, while adhesion is the force that makes water stick to a finger or a leaf surface.