What is viewed through an electron microscope?
(1) Electrons and other elementary particles
(2) Structure of bacteria and viruses
(3) Inside of human stomach
(4) Inside of the human eye
Answer: (2) Electron microscopes are used to observe a wide range of biological and inorganic specimens including microorganisms, cells, large molecules, biopsy samples, metals, and crystals. An electron microscope uses a beam of electrons to illuminate a specimen and produce a magnified image. An electron microscope (EM) has greater resolving power than a light-powered optical microscope because electrons have wavelengths about 100,000 times shorter than visible light photons. The electron microscope uses electrostatic and electromagnetic “lenses” to control the electron beam and focus it to form an image. Industrially, the electron microscope is often used for quality control and failure analysis.
