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We review the structure of atoms to describe allowed intra-atomic electronic transitions following dipole selection rules. Inner shell ionization is followed by characteristic X-ray emission or non-radiative de-excitation processes leading to Auger electrons that involve three atomic levels. Photon incidence also results in characteristic photoelectron emission, reflecting the energy distribution of the electrons in the solid. We present details of laboratory and synchrotron sources of X-rays, and discuss their detection by wavelength or energy-dispersive spectrometers, as well as microanalysis with X-ray (XRF), or electron (EPMA) incidence. Characteristic X-ray intensities are quantified in terms of composition using corrections for atomic number (Z), absorption (A), and fluorescence (F). Electron detectors use electrostatic or magnetic dispersing fields; two common designs are electrostatic hemispheric or mirror analyzers. Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS), used for surface analysis, require ultra-high vacuum. AES is a weak signal, best resolved in a derivative spectrum, shows sensitivity to the chemical state and the atomic environment, provides a spatially-resolved signal for composition mapping, and can be quantified for chemical analysis using sensitivity factors. Finally, we introduce the basics of XPS, a photon-in, electron-out technique, discussed further in §3.

The three tables that follow provide an easily accessible comparative summary of the key points and features of the major characterization methods discussed in the text. The techniques are classified into three broad groups/methods: spectroscopy/chemical, diffraction/scattering, and imaging. For each technique, a concise description of the method and its use is followed, in bullet form, by its salient details and other characteristics, such as resolution, sensitivity etc., as well as specimen requirements that determine its practice. A general estimate of cost and space requirements is also included, but needless to say, this is only a snapshot for comparison and is definitely subject to change with time.

Chemical substances such as gold and water provide paradigm examples of natural kinds: They are so central to philosophical discussions on the topic that they often provide the grounds for quite general philosophical claims—in particular that natural kinds must be hierarchical, discrete, and independent of interests. In this chapter I will argue that chemistry in fact undermines such claims. In what follows I will (i) introduce the main kinds of chemical kinds, namely chemical substances and microstructural species; (ii) critically examine some general criteria for being a natural kind in the light of how they apply to chemical kinds; and finally (iii) present two broad theories of how chemical substances are individuated. The primary purpose of this article is to bring scientific detail and sophistication to a topic—natural kinds—which has a long but not always honorable history in philosophy, but chemists can also learn something from these discussions. Chemistry is in the business of making general claims about substances, a fact which is embodied in the periodic table, as well as in the systems of nomenclature and classification published by the International Union of Pure and Applied Chemistry (IUPAC). At several points in the history of their subject, chemists appear to have faced choices about which general categories should appear in these systems. Understanding why these choices were made, and the alternatives rejected, gives us an insight into whether chemistry might have developed differently. This is central to understanding why chemistry looks the way it does today. So, what are the chemical kinds? Chemists study the structure and behavior of substances such as gold, water and benzene, and also of microscopic species such as gold atoms, and water and benzene molecules. They group together higher kinds of substances: groups of elements such as the halogens and alkali metals, broader groups of elements such as the metals, and classes of compounds that share either an elemental component (e.g., chlorides), a microstructural feature (e.g., carboxylic acids), or merely a pattern of chemical reactivity (e.g., acids).

The discovery of periodicity in the properties of the elements and its connection to their atomic weights is one of the most important advances in nineteenth-century chemistry. This chapter will consider the tables of John Newlands (1837–1898) and William Odling (1829–1921), which preceded that of Dmitrii Ivanovich Mendeleev (1834–1907). Mendeleev’s table was published in 1869, prior to his being aware of the UK precedents of his tabulation. The major portion of this chapter will extend the ideas advanced by Stephen Brush in The Reception of Mendeleev’s Periodic Law in America and Britain but will restrict itself to the dissemination of the periodicity concept within the United Kingdom. This will be monitored by recording its appearances in textbooks and examination papers, and in a wider context, by extracting data from Google Books. The periodic table has a rich history since its inception. It has evolved into many shapes, and indeed dimensions, yet retaining its essential periodic underpinning. In the United Kingdom it is seen as a “table,” whereas the French prefer “classification” and the Germans and Russians “system.” Mendeleev himself referred to his periodic law in his Faraday Lecture and never used the term “table,” thus it is ironic that his fame is linked to words that he appears never to have uttered. The arrangement of the elements in rows and columns is seen as a table, but why label it periodic? A related, more familiar word to non-chemists is periodical, normally referring to a magazine that appears at regular time intervals. Google Books is a powerful modern tool for investigating the usage of selected words or phrases over selected time intervals. The writer chose to use its advanced search for books in the English language. This meant that sources other than British, notably North American, are also included but the observed patterns are probably true for British books. The data compare the number of times the terms periodic table, periodic law, periodic classification, and periodic acid occurred in five-year intervals between 1870 and 1919.

The 1870s marked the onset of an exceptionally fruitful and dynamic period in the development of chemistry in the Czech Lands. University education and research in chemistry was taking place at several universities and technical universities, where the structure of the main chemical subjects developed gradually into organic, inorganic, analytical, physical, fermentation, and medical chemistry, just to mention the main specialties. At the same time, the process of the Czech National Revival led to the cultural, linguistic, social, and political emancipation of the modern Czech nation and stepwise almost entirely separated the linguistically Czech and German scientific communities in all their representations, including university education. In Prague, the divided German and Czech Polytechnics (and later Technical Universities) existed since 1869, whereas the Charles-Ferdinand University split into its Czech and German counterparts only in the years 1882 and 1883. The chemical community was organized in several professional associations that also reflected the ethnic division of the scientific scene. The Society of Czech Chemists, founded in 1866, had almost exclusively Czech membership, while a specialized German chemical association has never been created in the Czech Lands. This study deals with two closely intertwined themes: the reception of the periodic system in the Czech Lands and in Europe and the crucial role of the Czech chemist Bohuslav Brauner in this process. I am going to demonstrate a specific set of conditions that shaped the process of appropriation of this new scientific idea by not only scholarly argumentation, but also particular circumstances, in this case Slavic nationalism and Russophilia in the Czech society at the turn of the nineteenth century. The course of dissemination and reception of the periodic system also showed linkage to the linguistic emancipation of the Czech nation as reflected in the controversy over the Czech chemical terminology, where the periodic system served as argument to one party of the dispute.