3.2 the electron microscope

Question 1

what are the advantages of using the electron microscope?

Answer 1

• shorter wavelength have a higher resolving power
• electron beam could be focused using electromagnets

Question 2

how does a transmission electron microscope work?

Answer 2

• electron gun produces a beam of electrons and is focused on a specimen by a condenser electromagnet

Question 3

what are limitations of a transmission electron microscope?

Answer 3

• a vacuum system makes it unable to observe living organisms
• complex staining process
• extremely thin specimen
• man contain artrefacts

Question 4

what are artefacts?

Answer 4

not a part of natural specimen but is resulted from the way a specimen is prepared

Question 5

how does a scanning electron microscope work?

Answer 5

directs beam of electron on the surface and is passed back & forward in a regular pattern