Final answer:
A scanning electron microscope offers high-resolution 3-D images of the surface texture and shape of microscopic items by scanning them with a beam of electrons. It's valuable for detailed surface examination without requiring thin specimen sections like TEM does.
Step-by-step explanation:
A scanning electron microscope (SEM) is an exceptional tool for scientists wanting to study the surface texture and shape of objects at a microscopic scale. The SEM provides detailed maps of specimen surfaces by scanning them with a beam of electrons.
This technology is capable of magnification ranging from about 10 to 500,000 times, providing users with high-resolution, three-dimensional images of a variety of objects. Unlike the transmission electron microscope (TEM), which needs very thin sections to visualize internal structures like organelles, the SEM allows for visualization of larger surfaces, such as those of pollen grains, without the necessity of thin sample preparation.
During SEM analysis, specimens are typically dried, treated with fixatives to minimize artifacts, and then sputter-coated with a thin layer of metal such as gold to enhance the detection of secondary electrons which produce the image. Even though the resolution of SEM is lower than that of TEM, its ability to provide a 3-D view of the surface of samples makes it invaluable for studying the complexities of surface textures in detail.