touched? Modern methods of research in chemistry Since

Analytical methods in modern research You will:know the application areas of instrumental methods of analysis; How do scientists weigh molecules – the smallest particles of matter that can not be seen or touched? Modern methods of research in chemistry Since the mid of 20th century, fundamental changes have occurred in the methods of chemical research, involving a wide arsenal of means of physics and mathematics. The classical tasks of chemistry – the establishment of the composition and structure of substances – all are more successfully solved using the latest physical methods. An essential feature of theoretical and experimental chemistry has been the use of newest high-speed computing for quantum chemical calculations, the detection of kinetic regularities, the processing of spectroscopic data, the calculation of the structure and properties of complex molecules.The microchemical analysis allows performing analytical operations with quantities of substances hundreds of times smaller than in the method of conventional chemical analysis. Chromatography is a very important method, serving not only for analytical purposes but also for the separation of substances very similar in chemical properties in the laboratory and industrial scales. An important role is played by physicochemical analysis as one of the methods for determining the chemical composition and the nature of the interaction of components in aqueous solutions, molten solutions, and other systems. Graphical methods are also widely used. This variety of methods made it possible to clarify the concept of a chemical substance whose composition can be constant and variable. Predicted by Kurnakov, the class of nonstoichiometric compounds acquired great importance in materials science and a new field – solid state chemistry. 722027098 718799713  718799731 Study of chromatography is used to separate components of a plantLuminescent analysis, the method of labelled atoms, X-ray structural analysis, electron diffraction, polarography and other physicochemical methods of analysis are widely used in analytical chemistry. The use of radiochemical techniques makes it possible to detect the presence of only a few atoms of a radioactive isotope (for example, in the synthesis of transuranium elements).To establish the structure of chemical compounds, molecular spectroscopy, with which the distances between atoms, symmetry, the presence of functional groups, and other characteristics of the molecule are determined, is important, and the mechanism of chemical reactions is also studied. The electronic energy structure of atoms and molecules, the value of effective charges is clarified through emission and absorption X-ray spectroscopy. X-ray structural analysis methods study the geometry of molecules. 651111889    X-ray photoelectron spectrometer 724011067   Scientists are used Atomic Absorption Spectroscopy (AAS) to analyze heavy metals in sample solutions. For example, element Pb, Fe, Mn, Ag, etc. Ultraviolet–visible spectrometer   736266358The discovery of the interaction between electrons and atomic nuclei and between external and internal electrons made it possible to create methods for establishing the structure of molecules, such as nuclear magnetic resonance (NMR), electron paramagnetic resonance (EPR), nuclear quadrupole resonance, gamma-resonance spectroscopy. id:345070043 Magnetic resonance imaging (MRI) is a method of obtaining tomographic medical images for the study of internal organs and tissues using the phenomenon of nuclear magnetic resonance. Scottish chemist William Ramsay discovered noble gases. He used metallic magnesium to eliminate the oxygen and nitrogen chemically. He performed a spectroscopic analysis of the non-consumed gas and discovered in its spectrum the rays of an unknown element. He called this element argon, meaning “inert”. Tubes with inert gases excited with high voltage William Richards first measure of the atomic weights of a number of elements, and he was awarded the Nobel Prize winner in Chemistry in 1914.  5174154521. What is analytical chemistry?2. What is the difference between classical and instrumental methods of analytical chemistry?3. What is the main purpose of using mass spectrometry?atomic absorption spectroscopy – ???????-???????????? ????????????? / ??????-????????????? ?????????????internal electrons – ???? ??????????? / ?????????? ?????????magnetic resonance spectroscopy – ?????????-?????????? ????????????? / ????????-??????????? ?????????????