Adhesion studies Advantages of X-ray photoelectron spectroscopy (XPS) X-ray photoelectron spectroscopy (XPS) is an analytical technique that originated in the photoelectric effect, described by Einstein way back in 1905 [2]. Its measurements for characterization of solid surfaces are undertaken under vacuum conditions by retarding field methods. The application of the XPS techniques has several advantages as discussed in this topic. One of the advantages of this technique is that, the x-ray sources it employs, which include Al K (1486.6 eV) and Mg K (1253.6 eV) have very narrow x-ray lines below 0.9ev [1]. Therefore, this sources provide a good energy resolution hence making this technique applicable in many areas. Also, the electrons of the elements present in the solid surface are emitted at characteristic energies thus many elements can be identified easily. Moreover, XPS technique allows identification of all chemical states at any given element through quantification of the high resolution peaks [2]. …show more content…
Normally, the probing depth is between 4nm to 10nm and may even go to 20nm, indicating that this technique is sensitive to both surface and near surface layers [4]. XPS is a relatively non-destructive method of sample characterization, which depends on the nature of the sample and the power operation of the X-ray tube. Also, it is effective in identifying elements and their chemical states on surfaces and in quantitative analysis [5]. Further, XPS is able to detect the variance in chemical state between different samples. Furthermore, the oxidations states of different molecules can be differentiated in this
The purpose of the lab was to mimic the way Mendeleev placed the elements on the periodic table. Mendeleev was a Russian chemist who produced the first orderly periodic table. Frist, the way the periodic table has been classed alongside the atomic sum and the elements with related properties. Second, the objectives are observeing the physical states of common elements, and the progression of the periodic table, lastly speculate by determining the unknown elements established on the observed progression. As a group we tried to find out where the unknown elements should be placed. Finnly, the information that was given to help us with our process was the state, density, hardness, conductivity, melting point, and color.
Two scientific methods that could be used to identify me after I have been abducted and killed by a terrorist group would be x rays and fingerprint comparisons. Since the death and discovery has only been within the last 6 hours, the postmortem factors would not be a concern. Wild animals would not necessarily have enough time to start eating important evidence such as fingers for the fingerprint comparisons. The body would have started to set into rigor mortis but would not have decomped to the point of not being able to identify. The x ray would show the plate and screws in the elbow that would match medical records. If the body was not discovered until some time later, the plate and screws would be visible at the scene from where the body had decomposed. Fingerprints would be harder to get due to the state of the body.
How has the use of X-ray crystallography and mass spectrometry advanced our understanding of atomic and molecular structure?
To achieve this, the Heaven Lab uses computational chemistry and laser spectroscopy. For computational chemistry, they use ECP (Effective Core Potential) to correct the mass of the electron and the Darwin term for the actinide elements; following the theories of configuration interaction, density functional theory, and active space methods. Also, Thorium oxide (a specific actinide detectable through spectroscopy) has been tested using laser ablation of an actinide rod with Laser induced fluorescence, REMPI, PFI, PFI-ZEKE, and MCP. Ultimately, they have found that computational chemistry and laser spectroscopy are significant tools in identifying bonding properties of
The purpose of this lab is to use chemical and physical properties to identify a material. We are working on observing, inferring and predicting. We are learning if the properties of materials that appear similar can be used to tell them apart.
Koczanski, Krystyna; Xidos, James D. CHEM 1300 Laboratory Manual; UMSU Copy Centre: Winnipeg, MB, Canada, 2013, pp
The X-ray scarttering from the chlorine atoms and methoxy group on aniline ring are similar as they each possess 17 electrons, therefore they cannot be distinguished from
A heterogeneous beam of X-rays is produced by an X-ray generator and then it is projected toward the object. A certain amount of X-ray is absorbed by the object, which depends on the particular density and composition the object has. The
X-ray equipment safety requirements are essential and are part of improving the technical side of medical imaging with the goal of protecting the public and imaging professionals in the field. In order for x-ray equipment to be up to date and performing at a quality level, certain test, individuals, and standards are set to meet these
When Crick found flaw in V Vand’s proposed theory of X-ray diffraction by helices, he consulted his Cavendish colleague Bill Cochran. Both of the men, came up with a solution independently with different methods and the result agreed with X-ray diffraction diagram’s obtained Max Perutz during his research (Page 36). This development further increased the knowledge and application of the theory of how helices were supposed to look in X-ray photographs for Watson and Crick coalition. Watson not able to follow the mathematical expertise required to understand the theory, however, became well acquainted with the physical manifestation of helices on X-photographs of crystalline
The 3D models created a bridge from the abstract to the concrete. Ionization energy is difficult topic to for students to analyze and to “visualize.” The 3D model for ionization energy enabled the student to use visuals to identify which elements in the periodic table require the largest amount of energy to remove valence electrons. The 3D visual enabled them to notice the general periodic trends about each of the characteristics. In addition, students with limited language proficiency were able to relate the size of straws to the properties under investigation—these students determined that larger straws indicate larger ionization energy relative to other straws that represented different element ionization energies.
ABSTRACT: Rare earth elements or rare earth metals are a group of seventeen elements in the Periodic Table including Scandium, Yttrium and 15 Lanthanides with Z ranging continuously from 57 to 71. These elements encompass nearly all electronic, clean energy, and military technologies due to their unique physical and chemical properties. Despite world-wide usage of these elements, presently China bears a monopoly in rare earth market owing to its huge rare earth deposits. The ever increasing demand and restricted export of REE from China has forced counties around the world to explore resources available to them. Propelled by increasing demand and a need for self-sufficiency to provide for growing industry demands, India plans to triple its output by 2017.Though a number of conventional techniques are already in practice they are too costly and environmentally destructive to be used for the widely dispersed low grade resources. Furthermore, the processing of low grade ores would lead to generation of additional amount of wastes of complex nature. Thus, there is an urgent need to search for alternative rare earth mining techniques. For this reason Phytoextraction would be a better alternative. In
The higher the settings, the more intense the beam being output from the PID. An increase in exposure time will increase the intensity of the x-ray beam. But when the focal-film distance (FFD) increases, intensity decreases due to divergence of a beam produces a larger field.
An unknown material can be determined by using simple chemical tests and separations which is called as inorganic qualitative analysis. The separation of cations depends on the difference in their propensity to form precipitates. Separation scheme is used to classify cation into five groups on the basis of their physical and chemical behavior opposed to some reagents. Classification is based on whether there is formation of precipitates or not when metal cations react with the reagent. The five groups of cations and the characteristics of these groups are as follows:
Electron microscopes are generally microscopes that use electrons as a source of illumination to create an image, unlike light microscopes that relays on light. One of these types of microscopes is Scanning Electron Microscope (SEM), This microscope uses electrons to scan the surface of a sample giving an observer a highly magnified image of the sample. The electron microscope has been an amazing tool for research purposes around the world for many decades and the technique was discovered and developed throughout the years.