3.2 The electron microscope

Question 1

What are the 2 main advantages of an electron microscope?

Answer 1

1) electron beam has a short wavelength and the microscope can therefore resolve objects well
2) as electrons are negatively charged the beam can be focused using electromagnets

Question 2

Limitations of the TEM.

Answer 2

• whole system in a vacuum, can’t observe living organisms
• complex ‘staining’ process
• specimen must be very thin

Question 3

Limitations of the SEM.

Answer 3

• whole system in a vacuum, can’t observe living organisms
• complex ‘staining’ process

Question 4

What does a TEM observe?

Answer 4

the internal structures

Question 5

What does an SEM observe?

Answer 5

the surface and internal structures