Microscopes Flashcards
(6 cards)
1
Q
Total magnification of image
A
-Magnification of eyepiece x magnification of objective lens
2
Q
Magnification
A
size of image/size of object
3
Q
Maximum mag of light microscope
A
-x1500
-Pick points 500nm apart.
4
Q
Transmission electron microscopes
A
-Resolving power of 0.1nm.
-Beam of electrons onto specimen.
-2D black and white image.
-Denser parts absorb electrons, appear dark.
-Can magnify up to 2 million.
5
Q
Drawbacks of TEM/SEM
A
-Whole system must be in a vacuum (cannot be living specimen)
-May contain artefacts.
-Slow, expensive and complicated.
6
Q
Scanning electron microscope
A
-Directs beam of electron onto specimen.
-Detects scattering of electrons, relates to the contours of the specimen surface.
-Builds up a coloured 3D image.
-Resolution of 10nm.
