Surface tension effects of surface tension can be seen with ordinary water: Surface tension is visible in other common phenomena, especially when surfactants are used to decrease it: Surface tension, represented by the symbol "γ" (alternatively "σ" or "T"), is measured in force per unit length. Its SI unit is newton per meter but the cgs unit of dyne per centimeter is also used. For example, Surface tension can be defined in terms of force or energy. In terms of force: surface tension of a liquid is the force per unit length. In the illustration on the right, the rectangular frame, composed
Meniscus (liquid) in glass or other wettable containers. Conversely, a convex meniscus occurs when the particles in the liquid have a stronger attraction to each other than to the material of the container. Convex menisci occur, for example, between mercury and glass in barometers and thermometers. The formation of menisci is commonly used in surface science to measure contact angles and surface tension. In a contact angle measurement, the shape of the menisci is measured with a balance or optically with a digital camera. In a surface tension measurement, the measurement probe has a contact angle of zero and the surface tension