Cohesion: The phenomenon of attraction between
molecules of the same substance is called cohesion.
Adhesion: The phenomenon of attraction between
molecules of different substances is called adhesion.
Cohesive Force: The mutual force of attraction between
molecules of the same substance is called cohesive force.
Adhesive Force: The mutual force of attraction between
molecules of different substances is called adhesive force.
Intermolecular Binding Energy: The minimum energy
required to separate two molecules from each other's influence is called
intermolecular binding energy.
Molecular Range: The maximum distance
up to which the molecular force is effective is called the molecular
Molecular Forces: Molecular forces are of short range
and are effective only when the distance between molecules is of the order of
Normal Distance: The distance of separation between two
molecules where the intermolecular forces of attraction become zero is called
Sphere of Influence: If a sphere is drawn with a molecule
as centre and the molecular range as radius, all molecules lying within this
sphere will exert forces of attraction on each other. Such a sphere is called
a sphere of influence.
Surface Film: A thin film of a liquid near its surface
that has a thickness equal to the molecular range for that liquid is called
Cohesion Pressure: The downward cohesive force per unit
area of a liquid surface is called cohesion pressure.
Surface Tension: Surface tension is defined as the force
acting normally per unit length on either side of an imaginary line drawn on
the free surface of the liquid. This force is perpendicular to the line and
tangential to the surface of the liquid.
Surface Energy: The work done to increase the free surface
area of a liquid by unit area under isothermal conditions is called the free
surface energy of the liquid and it is numerically equal to the surface
Critical Temperature: The temperature at which the surface
tension of a liquid becomes zero is called critical temperature.
Wetting Agent: A wetting agent is a chemical used in dyeing
which reduces the angle of contact between the fabric and the dye.
Meniscus: The curved surface of a liquid when it is in
contact with a solid surface is called the meniscus.
Angle of Contact: For a liquid in contact with a solid,
the angle between the surface of the solid and the tangent drawn to the free
surface of the liquid at the point of contact measured from the side of the
liquid is called the angle of contact.
Capillary Tube: A tube with a very fine bore is called a
Capillarity: The rise or fall of a liquid in a capillary
tube is called capillarity.
Jurin's Law: It states that the
smaller the radius of a tube, greater is the rise or fall of liquid in it.