Meniscus ( liquid ) - wikipedia Meniscus ( liquid ) A : The bottom of a concave meniscus. B : The top of a convex meniscus. The meniscus ( plural : menisci, from the Greek for `` crescent '' ) is the curve in the upper surface of a liquid close to the surface of the container or another object, caused by surface tension. It can be either concave or convex, depending on the liquid and the surface. A concave meniscus occurs when the particles of the liquid are more strongly attracted to the container ( adhesion ) than to each other ( cohesion ), causing the liquid to climb the walls of the container. This occurs between water and glass. Water - based fluids like sap, honey, and milk also have a concave meniscus 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. Contents 1 Contact angle and surface tension 2 Measurement of volumes 3 Capillary action 4 References Contact angle and surface tension Menisci on a thin fiber. 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 can be obtained by measuring the mass of the menisci. This is typically done with a Wilhelmy plate. Measurement of volumes A meniscus as seen in a burette of colored water. ' 20.00 mL ' is the correct depth measurement. When reading a depth scale on the side of an instrument filled with liquid, such as a water level device, the meniscus must be taken into account in order to obtain an accurate measurement. Depth must be measured with the meniscus at eye level ( to eliminate parallax error ) and at the center of the meniscus, i.e. the top of a convex meniscus or the bottom of a concave meniscus. Manufacturers of glassware and other tools calibrate their measurement marks to account for the meniscus. This means that any instrument is calibrated for a specific liquid, usually water. Capillary action Menisci are a manifestation of capillary action, by which surface adhesion pulls a liquid up to form a concave meniscus or internal cohesion pulls the liquid down to form a convex meniscus. This phenomenon is important in transpirational pull in plants. When a tube of a narrow bore, often called a capillary tube, is dipped into a liquid and the liquid wets the tube ( with zero contact angle ), the liquid surface inside the tube forms a concave meniscus, which is a virtually spherical surface having the same radius, r, as the inside of the tube. The tube experiences a downward force of magnitude 2πrσ, where σ is the surface tension of the liquid. References ^ Jump up to : Moore, John W. ; Stanitski, Conrad L. ; Jurs, Peter C. ( 2005 ). Chemistry : The Molecular Science. Belmont, CA : Brooks / Cole. p. 290. Jump up ^ Biolin Scientific. `` Surface and interfacial tension White Paper ''. Jump up ^ `` Fluid Mechanics ''. Encyclopædia Britannica. Retrieved 14 November 2014. Retrieved from `` https://en.wikipedia.org/w/index.php?title=Meniscus_(liquid)&oldid=865104074 '' Categories : Fluid mechanics Greek words and phrases Hidden categories : Use dmy dates from April 2017 Talk Contents About Wikipedia বাংলা Беларуская Bosanski Català Dansk Deutsch Español فارسی Français Galego 한국어 Հայերեն Ido Italiano Magyar Nederlands 日本 語 Norsk nynorsk Polski Português Русский Slovenščina Svenska తెలుగు Українська 17 more Edit links This page was last edited on 21 October 2018, at 19 : 16 ( UTC ). Text is available under the Creative Commons Attribution - ShareAlike License ; additional terms may apply. By using this site, you agree to the Terms of Use and Privacy Policy. Wikipedia ® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization. About Wikipedia

Question: what do you call the curved upper surface of water
Answer: meniscus