Coursework.Info - Inspiration in an Instant

On the left is an image preview of every page of this document, and below are the first 150 words with formatting removed:

The Principles and Limitations of Scanning and Transmission Electron Microscopes Electron microscopes were first developed due to the limitations of light microscopes (3). The smallest object that can be viewed by any microscope is half the wavelength of light used, and objects smaller than this cannot be seen. This is because the object has to be large enough to interfere with the waves radiation. Light has a wavelength between 400-700nm, so the smallest object that can be viewed using visible light is 200nm(3). By the early 1930's all the possible scientific progress on understanding the inner parts of cells had been made, and scientists wanted to see more detail. Max Knoll and Ernst Ruska then developed the electron microscopes in 1931 (7). Electron microscopes use the same principles as light microscopes, but a beam of electrons is used instead of a beam of light. Electron beams have a wavelength of about 0.005nm....

To see the full version of this document, and 145,348 others