Microscopes Flashcards
1
Q
How does SEM work
A
A beam of electrons is passed onto a specimen which then scatters the electrons which are then detected and recorded.
2
Q
Advantages of SEM
A
Produces a 3D image in colour
Don’t need a thin specimen
3
Q
Advantages of TEM
A
Resolution is 0.1 nm; whereas SEM resolution is 20nm
4
Q
Disadvantages of both
A
Must be in a vacuum so specimen can’t be alive
Image may contain artefacts
5
Q
Equation for magnification
A
Size of image/ size of real object
6
Q
Resolution of a light microscope
A
200nm
7
Q
How does a TEM work?
A
Passes a beam of electrons through a thin specimen. The different structures either absorb or reflect the electrons
