33 Questions
What is the primary limitation of Light Microscopes that led to the development of Electron Microscopes?
Their limited resolution and magnification due to the physics of light
Who is credited with the development of the telescope and the first microscope?
Antoine Leeuwenhoek
What does the term 'resolution' describe in the context of microscopy?
The detail an image holds, quantifying how close lines can be to each other and still be visibly resolved
What is the 'depth of field' in an image?
The distance in front of and beyond the subject that appears to be in focus
Who formulated the relationship between resolution and the wavelength of light in microscopy?
Ernst Karl Abbe and Helmothz
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
What is the main advantage of using EDX in SEM?
It determines the presence and amounts of substances in the sample
What is the result of constructive interference of the scattered wavelengths from the periodically arranged scattering centers?
Diffraction
Why is it necessary to mount samples on stubs for SEM analysis?
To facilitate the handling of the sample
What is the main limitation of using SEM for sample analysis?
High capital cost
What is the characteristic of X-ray dispersions in EDX?
They are unique for each material
What is the phenomenon where X-ray beams appear to reflect off crystal cleavage faces at certain angles of incidence?
X-ray diffraction
What is the primary requirement for producing X-rays?
All of the above
What is the primary function of X-ray diffractometer in elemental analysis?
To detect the presence of all elements in a given system
Why is elemental analysis considered an exact science?
Because it provides accurate and rapid results
What is the problem encountered when expressing results in terms of oxides in chemical methods?
The form of oxide is unknown
What is the purpose of Laue method in X-ray diffraction?
To rotate the sample together with the X-ray source
What is the purpose of the metal apertures in a Scanning Electron Microscope?
To confine and focus the electron beam
What type of images can a Scanning Electron Microscope produce?
Both 2-D and 3-D images
What is the purpose of making the sample conductive in a Scanning Electron Microscope?
To reduce electron scattering
What is the function of the magnetic lens in a Transmission Electron Microscope?
To magnify the spatial variation of the electron beam
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
What is the range of magnification of a Transmission Electron Microscope?
Up to 50,000,000x
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
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
What is the principle behind Atomic Absorption Spectroscopy?
The absorption of light by atoms at specific wavelengths
What is the purpose of acid digestion in Atomic Absorption Spectroscopy?
To eliminate matrix interference
What is the advantage of using Flame Atomic Absorption Spectroscopy over other methods?
It is faster than other methods
What is the limitation of Atomic Absorption Spectroscopy in terms of the elements it can analyze?
It can only analyze metals and metalloids
What is the purpose of the hollow cathode lamp in Atomic Absorption Spectroscopy?
To provide the light source for the analysis
What is the main advantage of using Instrumental Methods over Classical Methods?
They are faster
What is the purpose of the monochromator in Atomic Absorption Spectroscopy?
To isolate the specific spectrum of the emitted light
What is the limitation of Atomic Absorption Spectroscopy in terms of its field use?
It is not portable
Learn about the basics of electron microscopy, its advantages over light microscopy, and its applications in material science. Discover how electron microscopes work and their capabilities in obtaining information on material topography, morphology, composition, and crystallographic information.
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