REVIEW EXERCISE (1)
(Anna University, NOV/DEC.2012)
Read the following passage and answer the questions given at the end:
An electron microscope is a sophisticated microscope that can magnify objects up to one
million times their original size. Unlike a traditional microscope, an electron microscope can reveal some
details of molecular structure and can be effectively used for chemical analysis. It has become an
invaluable analytical tool, widely used in medical and industrial research establishments.
There are two used types of electron microscopes: the Transmission Electron Microscope (TEM)
and the Scanning Electron Microscope. Transmission Electron Microscopes have extremely high
resolution and can provide detailed information about the structure of organisms most of which are
far too small to be seen at all with a normal optical microscope. TEMs can also be used for studying
the arrangement of atoms and molecules in metal and other materials. In fact, they are effectively
used, both to give information about the microstructure of new materials as they are being designed and also to help in the analysis of failures of materials as they are being designed and also the
in the analysis of failures of materials. Most TEMs operate at accelerating voltages in the range of
On the other hand, Scanning Electron Microscopes (SEM) have very different uses as they
very useful for looking at the surfaces of objects and can provide a completely different range
information. They may produce an extremely fine beam of electron which is swept to and from
the specimen. They are extremely useful in studying the details and contours of different surfans
e) Answer the following questions by choosing the best alternative option each
100,000 V.
They provide many other striking views of plant and animal cells that cannot be obtained by the
means. In the microelectronics industry, Scanning Electron microscopes have proved to be an eman
great asset. It is possible to use them to look in detail at the microcircuits that are now constri
on tiny silicon chips, the microscope is also used as an instrument to fabricate circuits by using the
electron beam as a writing tool, controlling it by a computer so that the required circuit is product
on a special surface.
QUESTIONS:
a) Answer the following questions:
0 What is the most remarkable feature of transmission electron microscope?
0 Can TEM help in achieving improved diagnosis of ailments? How?
What are the two important uses of electron microscopes in material science?
iv) Can SEM aid cancer research? How?
v) Can electron microscopes accurately describe the nature of the material under
examination?
b) Read the following statements and mark True or False based on the Text:
0 TEM has high resolving power.
D) SEM cannot be used in the micro electronics industry,
) SEM can provide striking views of animal cells.
iv) In TEM the electron beam is scanned to and fro across a specimen.
Electron microscopes are more useful than optical microscopes.
Some of the finest details of molecular structure can be revealed by
1. Traditional microscope
2. Optical microscopes
3. Electron microscopes
Answers
Electron Microscope
Explanation:
1. What is the most remarkable feature of the transmission electron microscope?
Transmission Electron Microscopes have extremely high resolution and can provide detailed information about the structure of organisms most of which are far too small to be seen at all with a normal optical microscope. They can also be used for studying the arrangement of atoms and molecules in metal and any other material.
2.Can TEM help in achieving an improved diagnosis of ailments? How?
Yes, the transmission electron microscope can help in achieving an improved diagnosis of ailment due to its extremely high resolution and magnifying capacity.
3.What are the two important uses of electron microscopes in material science?
The two important uses of the electron microscope in material science are details to the molecular structure which are useful for chemical analysis and its ability to magnify the objects up to one million times their original size can be used for diagnosis of various diseases.
4. Can SEM aid cancer research? How?
The scanning electron microscopes can be helpful and aid in cancer research as they can provide a closer look at the surfaces and provide a completely different range of information. They may produce an extremely fine beam of electron which is swept to and from the specimen.
5. Can electron microscopes accurately describe the nature of the material under examination?
The electron microscope has proven to be a valuable asset as it can accurately describe the nature of the material under examination.
b)
1. True
2. False
3. True
4. False
5. True
Q. Some of the finest details of the molecular structure can be revealed by Electron Microscopes.