Question

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 forstudying 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. Most TEMs operate at

accelerating voltages in the range of 50-100,000V.

On the other hand, Scanning Electron Microscopes

(SEM) have very different uses as they are very

useful for looking at the surfaces of objects and

can provide a completely different range of

information. They may produce an extremely fine

beam of electron, which is swept to-and from

across the specimen. They are extremely useful in

studying the details and contours of different

surfaces. They provide many other striking views

of plant and animals cells that cannot be obtained

by other means. In the microelectronics industry,

Scanning Electron Microscopes have proved to be

an equally great asset. It is possible to use them to

look in detail at the microcircuits that are now

constructed 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 produced on a special surface.(i) Answer the following questions

(a) What is the most remarkable feature of

transmission electron microscope?

(b) Can TEM help in achieving improved

diagnosis of ailments? How?

(c) What are the two important uses of

electron microscopes in materials

science?

(d) Can SEM aid cancer research? How?

(e) Can electron microscopes accurately

describe the nature of the material

under examination?

(ii) Read the following statements and mark

True or False based on the text:

(a) TEM has high resolving power.

(b) SEM cannot be used in the

microelectronics industry.

(c) SEM can provide striking views of

animal cells.

(d) In TEM the electron beam is scanned

to-and-from across a specimen.

(e) Electron microscopes are more useful

than optical microscopes.​

Answer 1

Answer:

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