Question

What is the difference between scanning and transmission electron microscopy?

Answer 1

Hint: Hint –
Electrons are so small that, like photons in light, they behave like waves. A beam of electrons travels past the specimen, then via a series of magnifying lenses. The picture is the result of electron scattering by atoms in the specimen.
SEM– Scanning electron microscopy
TEM– Transmission electron microscopy

Complete answer:

SEM	TEM
SEM is based on scattered electrons	TEM is based on transmitted electrons.
SEM focuses on the surface and composition of the sample. As a result SEM simply reveals the morphology of materials.	TEM offers information on the internal composition. As a result, TEM can reveal various sample properties such as morphology, crystallisation, stress, and even magnetic domains.
The sample in SEM does not require to be sliced thin.	The sample in TEM must be sliced thinner
SEM can analyse a big amount of samples at once.	TEM can only analyse a limited amount of samples at a time.
Surfaces, powders, polished and etched microstructures, IC chips, and chemical segregation are all imaged with SEM.	TEM is used to image dislocations, small precipitates, grain boundaries, and other defect structures in solids.
SEM images are displayed on monitors; SEM also gives a 3-dimensional image, whilst TEM displays a 2-dimensional image.	TEM images are displayed on fluorescent screens
SEM has 0.5 to 4nm resolution.	The resolution of TEM is significantly higher than that of SEM. Its resolution is 0.1 to 0.3nm.

Note –
Electron microscopy has become a standard research technique in medicine and biology. Today, electron microscopy is used in diagnostics and biopsies of the liver, kidney, muscle, nerves, and intestine, as well as in hygiene and virology, and especially in molecular biology.