4. microscopy

• microscopy is an instrument designed to produce magnified visual or photographic images of small images.
• scanning electrons microscope allows scientists to view a universe too small to be seen with a light microscope. It does not use light waves; it uses electrons to magnify objects up to two million times.
• transmission electron microscope uses electrons, but instead of scanning the surface (as with SEM's), electrons are passed through very thin specimens.
• brightfield microscope uses light from the lamp source under the microscope stage to illuminate the specimen and shows clear magnification.
• darkfields microscope is a special aperture is used to focus incident light, meaning the background stays dark. The light does not pass directly through the sample being studied.
• phase contrast microscope is useful for looking at specimens that are both colorless and transparent. Converted into a change in the amplitude/intensity of light.
• fluorescence microscope used to observe the specimen, it begins where a molecule absorbs light of high frequency and emits light of lower frequency.
• focal length distance from the principal point to the focal of a lens.
• parfocal Objectives that can be changed with minimal or no refocusing.
• working distance is a distance between the front end of a microscope objective and the surface of the workpiece at which the sharpest focusing is obtained.
• resolution determines how finely a lens is able to distinguish the details of a specimen.
• magnification degree of increase in size of the optical image over the actual size of the object being viewed.
• depth focus is a distance between the two planes defines the limits of acceptable image sharpness when the microscope is focused on an object.
• numerical aperture indicates the resolving power of an objective lens. The larger the numerical aperture value, the finer the detail that can be seen.
• beaker is a cylindrical container that has a small spout to aid in pouring and a flat base.
• erlenmeyer flask slanted sides and narrow necks allow the contents to be mixed by swirling without the risk of spills, which is useful for titrations and for boiling liquids.
• Volumetric flask usually pear-shaped, with a flat bottom, and made of glass or plastic. Used for precise dilutions and preparation of standard solutions.
• graduated cylinder has a narrow, cylindrical shape. Used to measure the volume of a liquid. Each marked line on the graduated cylinder represents the amount of liquid that has been measured.
• test tube thin glass tube closed at one end. Used to hold, mix, or heat small quantities of solid or liquid chemicals for laboratory testing or experiments.
• test tube rack sed when various different solutions are needed to work with simultaneously, for safety reasons, for safe storage of test tubes, and to ease the transport of multiple tubes.
• test tube holder made from wood or metal. Used to hold and manipulate test tubes safely and secure
• test tube brush used for cleaning test tubes and narrow mouth laboratory glassware.
• stirring rod usually made of solid glass, about the thickness and slightly longer than a drinking straw, with rounded ends.
• medicine dropper used to transport a measured volume of liquid, often as a media dispenser.
• crucible container that can withstand very high temperatures and is used for metal, glass, and pigment production as well as a number of modern laboratory processes.
• crucible tong used to safely move a piece of equipment called a crucible that contains potentially dangerous materials that must be handled very carefully.
• evaporating dish used for the evaporation of solutions and supernatant liquids, and sometimes to their melting point.
• mortar and pestle used to crush up solid chemicals into smaller pieces or to grind solids into fine powder.
• glass funnel is a tube or pipe that is wide at the top and narrow at the bottom.  Used for guiding liquid or powder into a small opening.
• watch glass is a Circular concave piece of glass used in chemistry as a surface to evaporate a liquid, to hold solids while being weighed, as a cover for a beaker, and for heating a small amount of substance.
• wash bottle is a squeeze bottle with a nozzle.  Used to rinse various pieces of laboratory glassware, such as test tubes and round bottom flasks.
• dissecting tool kit used to dissect animals, and it consists of all the necessary tools required to carry out the process of dissection.
• dissecting pan Used to hold the sample and allow the scientist to study the characteristics of the sample with clarity.
• wire gauze sheet of thin metal that has net-like patterns or a wire mesh. Placed on the support ring that is attached to the retort stand between the Bunsen burner and the glassware to support the beakers, flasks, or other glassware during heating.
• iron clamp Used to hold things and is placed in an iron stand to elevate other equipment.
• iron stand Used to support laboratory equipment above the work surface.
• tripod Used in a laboratory to support various laboratory glassware, ceramic ware, equipment, etc.
• glass slide It is a long, thin piece of glass that specimens are placed on for study under a microscope.
• alcohol lamp Used to produce an open flame. It can be made from either aluminum or glass.
• bunsen burner Produces a single open gas flame, which is used for heating, sterilization, and combustion.