Module 4 - SET C

Question 1

technical field of using microscopes to view objects and areas of objects that cannot be seen with the naked eye

Answer 1

Microscopy

Question 2

Types of Microscopy

Answer 2

Optical
Electron
Scanning Probe

X-ray Microscopy

Question 3

most powerful light microscopes provide only enough magnification to view objects larger than 200 nm

Answer 3

Electron Microscopy

Question 4

Why can the most powerful light microscopes only view objects larger than 200 nm

Answer 4

due to wavelength of visible light

Question 5

Who experimented with magnetic lenses for focusing electron beams and realized that it was possible to take advantage of smaller wavelength of electrons to create an imaging device theoretically capable greater magnification than a light microscope?

Answer 5

Ernst Ruska (1928)

Question 6

Who built the first electron microscope?

Answer 6

Ernst Ruska and Max Knoll

Question 7

When is the first electron microscope built?

Answer 7

1931

Question 8

Although it was no more powerful than a light microscope, it had proved the concepts of using focused electron beams for microscopic imaging

Answer 8

first electron microscope

Question 9

Who proved the concept of using focused electron microscope imaging?

Answer 9

Max Knoll and Ernst Ruska

Question 10

When is the electron microscope that surpassed the resolving power of light microscopes built?

Answer 10

1933

Question 11

How many times are electron microscopes more capable of viewing objects than light microscopes now?

Answer 11

1000 to 2500 smaller that what can be seen by the most powerful light microscopes

Question 12

use a beam of highly accelerated electrons

Answer 12

electron microscopes

Question 13

What are the two most common types of Electron Microscopes?

Answer 13

Transmission Electron Microscopy (TEM)
Scanning Electron Microscope (SEM)

Question 14

similar in light microscopy in that the beam passes through a very thinly sliced sample to provide an image on the other side

Answer 14

Transmission Electron Microscopy

Question 15

since electrons are not visible to the eye, the image is made by focusing the electron beam onto a view screen coated with some material that fluoresces (emits visible light) in response to the incoming electrons

Answer 15

Transmission electron microscopy

Question 16

image can be further enhanced using detectors similar to those found in digital cameras

Answer 16

Transmission electron microscopy

Question 17

electron beam is gradually scanned across the surface of the specimen

Answer 17

scanning electron microscope

Question 18

At each point on the surface some of the intensity of the electron beam is lost. This decrease of intensity can be measured in a variety of ways and can be converted into a surface image of the object

Answer 18

Scanning electron microscopy

Question 19

is only about 1/10 as powerful as TEM, but it provides a more three-dimensional image instead of a cross-sectional slice of the specimen

Answer 19

Scanning Electron Microscopy

Question 20

provides magnified images similar to those of SEM

Answer 20

Atomic Force Microscopy (AFM)

Question 21

works by moving mechanical probe across the surface of the object being scanned

Answer 21

Atomic Force Microscopy

Question 22

provides true, three-dimensional information about the objects

Answer 22

Atomic Force Microscopy

Question 23

There are several variations of AFM that vary somewhat in how data are collected and in how the probe is manipulated. All are part of the more general class of techniques called

Answer 23

Scanning probe microscopy

Question 24

keep the probe a constant distance from the object’s surface in order to avoid the possibility of the probe damaging or deforming the surface of the object being scanned

Answer 24

more advanced techniques of AFM and SPM