Microscopes

Question 1

Magnification

Answer 1

The extent to which the image is larger than the object being viewed

Question 2

Resolution

Answer 2

The ability of a microscope to distinguish between structures that are very close together

Question 3

Light Microscopes

Answer 3

• Use lenses to focus rays of light through the specimen
  -Light passed through lenses responsible for magnification and resolution
  -Light that isn’t absorbed is transmitter to the eye through the objective and eyepiece lens

Question 4

Electron Microscopes

Answer 4

-Beams of electrons are used, bent and focused by electromagnetic lenses
- Electron Beams have a shorter wavelength resulting in passing objects closely together, providing a much better resolution
- Magnification of up to x500,000

Question 5

TEM

Answer 5

• Electron beams are transmitted through the material
• Specimen needs to be extremely thin since electrons are much more easily blocked than light
  -Denser parts of Specimen absorbs more light
  -Other parts allow light to pass through to hit the screen, which fluoresces, and these parts appear bright

Question 6

SEM

Answer 6

• Beams of electrons are bounced off the surface of the specimen and creates an image from the electrons that are reflected from the surface
• Specimen used for SEM is thicker than ones used for TEM, as electrons don’t need to penetrate through
• Electrons are scattered by the specimen but is dependent on the contours of the specimen surface, a 3 dimensional image is produced