Question

What are the major differences between an optical (or light) microscope and an electron microscope?

Answer 1

Step-by-step explanation:

What is the difference between Optical Microscope and Electron Microscope?

Light microscopy uses electromagnetic radiation in the form of visible light for imaging. The wavelength ( λ ) of visible light falls within the range of 400–700 nm. For a microscope, the resolution limit is:

R=0.61λNA

(where NA is the numerical aperture, a dimensionless quantification of acceptable angle range and index of refraction).

From looking at this equation, you can see that the resolution is proportional to the wavelength. A given microscope can only image objects roughly larger than 1/2 the wavelength of the source.

TEM beats the diffraction limit of light by using a source with a shorter wavelength than photons — electrons!

From de Broglie, we know that the wavelength of a particle can be found by:

λ=hp

(where h is planck's constant and p is the mo/me////

ntum of the particle)

In a TEM, at a given accelerating voltage (and neglecting relativistic effects), the wavelength of the propagating electrons are:

λ=h(√2meV)

The wavelength varies with the voltage, but theoretically has no limit. A commonly used voltage is 100 keV, which would result in a wavelength of 3.70 pm, much smaller than the wavelengths of visible photons.

Answer 2

The light microscope is also known as an optical microscope. It is an instrument that uses light rays and lenses to enlarge images of microorganisms and other small entities. On the other hand, an electron microscope is an instrument that uses electron beams to capture an image and enlarge it.

I hope it helps a little.