An electron microscope must use electromagnet "lenses" shaped like donuts to direct the electrons onto the specimen. Why?
A) Electrons are particles but there are other particles in air as well. Without a vacuum, the electrons would strike and be scattered by the particles within the air.
B) Electrons are highly radioactive, and the chamber must be completely sealed to prevent them from escaping and contaminating the lab area.
C) This is the method for fixing the specimen to the slide grid for an electron microscope. Without fixing the specimen by vacuum, it would slide off and we wouldn't be able to visualize it.
D) All of the answer choices are True.
E) None of the answer choices is True.

Question

Quizplus · Accepted Answer

Electrons are easily scattered by other particles, so a vacuum is needed to eliminate any obstacles that could cause the electrons to change direction or lose energy while traveling toward the specimen. This is why the chamber in an electron microscope is sealed and a vacuum is maintained. The shaped electromagnet lenses are used to focus the electrons onto the specimen.

An Electron Microscope Must Use Electromagnet "Lenses" Shaped Like Donuts