Microscopes

Question 1

What is the definition of resolution?

Answer 1

The ability to distinguish between 2 separate points

Question 2

How does a TEM work?

Answer 2

A beam of electrons is passed through the specimen. Denser areas of the specimen absorb more electrons, appearing darker

Question 3

What are the limitations of a TEM?

Answer 3

•system must be in a vacuum- can’t observe living specimens
•complex specimen preparation
•specimen must be thin
•2D image

Question 4

How does a SEM work?

Answer 4

Pass a beam of electrons over the surface. The electrons are scattered by the specimen.

Question 5

What are the main differences between a TEM & SEM?

Answer 5

•SEM can build 3d images whereas TEM can only make 2d
•TEM has higher resloving power
•SEM can be in colour