Cesium elemental properties

Rubidium [7440-17-7] Rb, is an alkali metal, ie, ia Group 1 (lA) of the Periodic Table. Its chemical and physical properties generally He between those of potassium (qv) and cesium (see Cesiumand cesium compounds Potassium compounds). Rubidium is the sixteenth most prevalent element ia the earth s cmst (1). Despite its abundance, it is usually widely dispersed and not found as a principal constituent ia any mineral. Rather it is usually associated with cesium. Most mbidium is obtained from lepidoHte [1317-64-2] an ore containing 2—4% mbidium oxide [18088-11-4]. LepidoHte is found ia Zimbabwe and at Bernic Lake, Canada. 

The periodic table orders the elements in a way that helps chemists understand why atoms behave as they do. What makes fluorine react violently with cesium while its nearest neighbor neon is reluctant to react with anything In other words, what gives the elements their properties and what order lies below the surface of their seemingly random nature Scientists know now that the periodicity of the elements is due largely to recurring patterns in their electron configurations. 

The placement of an unknown element with an atomic number of 87 in group 1, period 7 of the periodic table was one of Dimitri Mendeleevs ideas based on the chemical properties and physical characteristics of the other alkali metals. In the late nineteenth century, Mendeleev named this unknown element eka-cesium and predicted its properties based on what was known of cesium s placement on the periodic table. This led to worldwide searches for element number 87, which were not all successful but which did result in proposed names for eka-cesium (moldavium, virginium, russium). 

The properties of this new element left no doubt that it was the missing alkali, eka-cesium, number 87. In 1946 Mile. Perey suggested that the name actinium K be kept for the naturally occurring isotope which resulted from the decay of actinium, but that element 87 in general... 

To investigate the effect of alcohol hydrogen-bond donor (HBD) strength in a systematic way, a series of modifiers possessing a common 4-teri-octylphenoxy ethanol core element were prepared, in which the properties of the substituent attached to the alcohol carbon atom were varied. These modifiers were evaluated with respect to both the cesium extraction strength they afforded when used in combination with BC6 and the HBD strength of the solvent as assessed using the solvatochromic parameter E. ... 

Mendeleev had determined some physical and chemical properties of elements before they were discovered and gave these unknown elements names such as eka-aluminum, eka-silicon, eka-boron, eka-cesium and eka-iodine. 

The existence of these different practices was not sufficient to create a discipline or subdiscipline of physical chemistry, but it showed the way. One definition of physical chemistry is that it is the application of the techniques and theories of physics to the study of chemical reactions, and the study of the interrelations of chemical and physical properties. That would mean that Faraday was a physical chemist when engaged in electrolytic researches. Other chemists devised other essentially physical instruments and applied them to chemical subjects. Robert Bunsen (1811—99) is best known today for the gas burner that bears his name, the Bunsen burner, a standard laboratory instrument. He also devised improved electrical batteries that enabled him to isolate new metals and to add to the list of elements. Bunsen and the physicist Gustav Kirchhoff (1824—87) invented a spectroscope to examine the colors of flames (see Chapter 13). They used it in chemical analysis, to detect minute quantities of elements. With it they discovered the metal cesium by the characteristic two blue lines in its spectrum and rubidium by its two red lines. We have seen how Van t Hoff and Le Bel used optical activity, the rotation of the plane of polarized light (detected by using a polarimeter) to identify optical or stereoisomers. Clearly there was a connection between physical and chemical properties. 

Fundamental atomic and physical properties of the alkali metals are given in Tables 1, 2, and 3. The elements are characterized by having electron configurations each with a single s orbital electron outside a noble gas core (see Table 1). Sodium and cesium are mononucUdic so that their relative atomic masses are known extremely accurately in effect, the same can be written for potassium and rubidium since their isotopes (of which there are three and two, respectively) have... 

The elements of the first group, lithium, sodium, potassium, rubidium, and cesium, are soft, silvery-white metals with great chemical reactivity. These elements are called the alkali metals. These metals are excellent conductors of electricity. Some of their physical properties are given in Table 91. It can be seen from the table that they melt at low temperatures—four of the five metals melt below the boiling point of water. The metals lithium, sodium, and potassium are lighter than water. 

Metals easily form alloys with other metals. The presence of even a small amount of another element in a metal severely affects its properties, as in the case of carbon in iron. Mercury, cesium, and gallium exist as liquids at room temperature. 

Pure elements at room temperature and atmospheric pressure can be solids, liquids, or gases. Some elements are colorless. Others, like the ones shown in Figure 1, are colored. Despite the differences between elements, groups of elements share certain properties. For example, the elements lithium, sodium, potassium, rubidium, and cesium can combine with chlorine in a 1 1 ratio to form LiCl, NaCl, KCl, RbCl, and CsCl. All of these compounds are white solids that dissolve in water to form solutions that conduct electricity. 

Sodium and oxygen combine to form sodium oxide, which has the formula Na20. Use the periodic table to predict the formulas of the oxides of potassium, rubidium, and cesium. What periodic property of the elements are you using ... 

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