unit 2, microscopes

Question 1

process of scanning electron microscope

Answer 1

1) electrons shot down on specimen from above
2) beam passed back and forth across specimen
3) electrons are scattered depending on contour of the specimen
4) cathode ray tube gathers knocked off electrons
5) 3D image made

Question 2

process of transmission electron microscope

Answer 2

1) electrons shot down from above onto specimen
2) electron passses through thin part of specimen
3) parts of speciment that absorb the elecrrons become darker ones that pass through are light
4) picture photographed as photomicrograph in 2D

Question 3

why are electron microscopes inside a vacuum

Answer 3

so electrons wont collide with air particles

Question 4

limitations electron microscope

Answer 4

high energy , expensive , only in black and white , specimen has to be dead, complex staining required , artefacts may be on results, can’t be moved around, transmission electon microscope can damage the specimen

Question 5

in transmission can you see inside of the cell

Answer 5

yes, electrons pass through thin part of the specimen

Question 6

what can u see with scanning

Answer 6

the outline

Question 7

why does electron microscopes have better resolution

Answer 7

due to electrons having a shorter wavelength than light

Question 8

magnification definition

Answer 8

How many times image size is bigger than the actual size

Question 9

Why does specimen have to be dead

Answer 9

due to the electron beam destroying the specimen