Electron Microscopy Fundamentals

What is the primary limitation of Light Microscopes that led to the development of Electron Microscopes?

Their ability to only image living specimens
Their limited resolution and magnification due to the physics of light (correct)
Their inability to provide information on material composition
Their requirement for specialized sample preparation

Who is credited with the development of the telescope and the first microscope?

Ernst Karl Abbe
Antoine Leeuwenhoek (correct)
Galileo Galilei
Robert Hooke

What does the term 'resolution' describe in the context of microscopy?

The type of specimen that can be imaged
The maximum magnification achievable
The detail an image holds, quantifying how close lines can be to each other and still be visibly resolved (correct)
The depth of field in an image

What is the 'depth of field' in an image?

The distance in front of and beyond the subject that appears to be in focus (B) Signup and view all the answers

Who formulated the relationship between resolution and the wavelength of light in microscopy?

Ernst Karl Abbe and Helmothz (C) Signup and view all the answers

What is the purpose of applying an ultra-thin coating of electrically conducting material to the sample?

To prevent the accumulation of static electric fields at the specimen (A) Signup and view all the answers

What is the main advantage of using EDX in SEM?

It determines the presence and amounts of substances in the sample (D) Signup and view all the answers

What is the result of constructive interference of the scattered wavelengths from the periodically arranged scattering centers?

Diffraction (D) Signup and view all the answers

Why is it necessary to mount samples on stubs for SEM analysis?

To facilitate the handling of the sample (A) Signup and view all the answers

What is the main limitation of using SEM for sample analysis?

High capital cost (C) Signup and view all the answers

What is the characteristic of X-ray dispersions in EDX?

They are unique for each material (B) Signup and view all the answers

What is the phenomenon where X-ray beams appear to reflect off crystal cleavage faces at certain angles of incidence?

X-ray diffraction (C) Signup and view all the answers

What is the primary requirement for producing X-rays?

All of the above (D) Signup and view all the answers

What is the primary function of X-ray diffractometer in elemental analysis?

To detect the presence of all elements in a given system (D) Signup and view all the answers

Why is elemental analysis considered an exact science?

Because it provides accurate and rapid results (D) Signup and view all the answers

What is the problem encountered when expressing results in terms of oxides in chemical methods?

The form of oxide is unknown (A) Signup and view all the answers

What is the purpose of Laue method in X-ray diffraction?

To rotate the sample together with the X-ray source (B) Signup and view all the answers

What is the purpose of the metal apertures in a Scanning Electron Microscope?

To confine and focus the electron beam (C) Signup and view all the answers

What type of images can a Scanning Electron Microscope produce?

Both 2-D and 3-D images (A) Signup and view all the answers

What is the purpose of making the sample conductive in a Scanning Electron Microscope?

To reduce electron scattering (B) Signup and view all the answers

What is the function of the magnetic lens in a Transmission Electron Microscope?

To magnify the spatial variation of the electron beam (B) Signup and view all the answers

What is the advantage of the Everhart-Thornley detector in a Scanning Electron Microscope?

It allows the formation of images using the secondary electron signal (B) Signup and view all the answers

What is the range of magnification of a Transmission Electron Microscope?

Up to 50,000,000x (D) Signup and view all the answers

What is the primary goal of Chemical Analysis in the context of mineral identification?

To separate the individual elements from each other in a sample (D) Signup and view all the answers

What is the main difference between Complete Chemical Analysis and Selective Chemical Analysis?

The goal of the analysis, whether it is to identify all elements or a specific one (D) Signup and view all the answers

What is the principle behind Atomic Absorption Spectroscopy?

The absorption of light by atoms at specific wavelengths (B) Signup and view all the answers

What is the purpose of acid digestion in Atomic Absorption Spectroscopy?

To eliminate matrix interference (B) Signup and view all the answers

What is the advantage of using Flame Atomic Absorption Spectroscopy over other methods?

It is faster than other methods (D) Signup and view all the answers

What is the limitation of Atomic Absorption Spectroscopy in terms of the elements it can analyze?

It can only analyze metals and metalloids (C) Signup and view all the answers

What is the purpose of the hollow cathode lamp in Atomic Absorption Spectroscopy?

To provide the light source for the analysis (A) Signup and view all the answers

What is the main advantage of using Instrumental Methods over Classical Methods?

They are faster (A) Signup and view all the answers

What is the purpose of the monochromator in Atomic Absorption Spectroscopy?

To isolate the specific spectrum of the emitted light (B) Signup and view all the answers

What is the limitation of Atomic Absorption Spectroscopy in terms of its field use?

It is not portable (D) Signup and view all the answers