Electron microscopes have certain advantages over optical microscopes: The biggest advantage is that they have a higher resolution and are therefore also able of a higher magnification (up to 2 million times). Light microscopes can show a useful magnification only up to 1000-2000 times. This is a physical limit imposed by the wavelength of the light. Electron microscopes therefore allow for the visualization of structures that would normally be not visible by optical microscopy.
berm (plural berms) A narrow ledge or shelf, as along the top or bottom of a slope. A raised bank or path, especially the bank of a canal opposite the towpath. A terrace formed by wave action along a beach. A mound or bank of earth, used especially as a barrier or to provide insulation.
berm - a narrow ledge or shelf typically at the top or bottom of a slope. 2. berm - a narrow edge of land (usually unpaved) along the side of a road; the car pulled off onto the shoulder. shoulder. edge - the outside limit of an object or area or surface; a place farthest away from the center of something; the edge of the leaf is wavy; she sat on the edge of the bed; the water's edge.