Cadmium Facts - Periodic Table

Cadmium Facts - Periodic Table Cadmium Atomic Number 48 Cadmium Symbol Cd Cadmium Atomic Weight 112.411 Cadmium Discovery Fredrich Stromeyer 1817 (Germany) Electron Configuration [Kr] 4d10 5s2 Word Origin Latin cadmia, Greek kadmeia - ancient name for calamine, zinc carbonate. Cadmium was first discovered by Stromeyer as an impurity in zinc carbonate. Properties admium has a melting point of 320.9Â °C, boiling point of 765Â °C, spcific gravity of 8.65 (20Â °C), and a valence of 2. Cadmium is a blue-white metal soft enough to be easily cut with a knife. Uses Cadmium is used in alloys with low melting points. It is a component of bearing alloys to given them a low coefficient of friction and resistance to fatigue. Most cadium is used for electroplating. It is also used for many types of solder, for NiCd batteries, and to control atomic fission reactions. Cadmium compounds are used for black and white television phosphors and in the green and blue phosphors for color television tubes. Cadmium salts have wide application. Cadmium sulfide is used as a yellow pigment. Cadmium and its compounds are toxic. Sources Cadmium is most commonly found in small quantities associated with zinc ores (e.g., sphalerite ZnS). The mineral greenockite (CdS) is another source of cadmium. Cadmium is obtained as a by-product during treatment of zinc, lead, and copper ores. Element Classification Transition Metal Density (g/cc) 8.65 Melting Point (K) 594.1 Boiling Point (K) 1038 Appearance soft, malleable, blue-white metal Atomic Radius (pm) 154 Atomic Volume (cc/mol) 13.1 Covalent Radius (pm) 148 Ionic Radius 97 (2e) Specific Heat (20Â °C J/g mol) 0.232 Fusion Heat (kJ/mol) 6.11 Evaporation Heat (kJ/mol) 59.1 Debye Temperature (K) 120.00 Pauling Negativity Number 1.69 First Ionizing Energy (kJ/mol) 867.2 Oxidation States 2 Lattice Structure Hexagonal Lattice Constant (Ã…) 2.980 Lattice C/A Ratio 1.886 References: Los Alamos National Laboratory (2001), Crescent Chemical Company (2001), Langes Handbook of Chemistry (1952), CRC Handbook of Chemistry Physics (18th Ed.) Return to the Periodic Table Chemistry Encyclopedia

Islamic Mullah

Islamic Mullah Mullah is the name given  to teachers or scholars of Islamic learning or the leaders of mosques. The term is usually a mark of respect but can also be used in a derogatory manner and is primarily used in Iran, Turkey, Pakistan, and the former Soviet republics of Central Asia. In Arabic-speaking lands, an Islamic cleric is called an imam or Shayk  instead. Mullah is derived from the Arabic term mawla, which means master or the one in charge. Throughout Southern Asias history, these rulers of Arabic descent have led cultural revolutions and religious war alike. However, a mullah is general a local Islamic leader, although sometimes they rise to national prominence. Usage in Modern Culture Most often, Mullah refers to Islamic scholars well-versed in the sacred law of the Quran, however, in  Central  and  East Asia, the term mullah is used on a local level to refer to mosque leaders and scholars as a sign of respect.   Iran is a unique case in that it uses the term in a pejorative manner, referring to low-level clerics as mullahs because the term derives from Shiite  Islam wherein the Quran casually mentions mullah multiple times throughout its pages while Shia Islam is the dominant religion of the country. Instead, clergymen and religious leaders use alternative terms to refer to their most respected members of the faith.   In most senses, though, the term has disappeared from modern usage except to mock those who are overly devout in their religious pursuits - a sort of insult for reading the Quran too much and assuming oneself the Mullah referred to in the sacred text. Respected Scholars Still, there is some respect behind the name mullah - at least for those who regard those well versed in religious texts as mullahs. In these cases, the astute scholar must have a firm understanding of all things Islam - especially as it pertains to the contemporary society wherein the hadith (traditions) and fiqh (law) are equally important. Oftentimes, those considered to be mullah will have memorized the Quran and all of its important teachings and lessons - though often times throughout history uneducated common folk would misname visiting clerics mullahs because of their vast knowledge (comparatively) of the religion. Mullahs can also be considered teachers and political leaders. As teachers, mullahs share their knowledge of religious texts in schools called madrasas in matters of Shariah law. They have also served in positions of power, such as the case with Iran after the Islamic State took control in 1979. In Syria, Mullahs play an important role in the ongoing conflict between rival Islamic groups and foreign adversaries alike, valuing the protection of Islamic law while staving off Islamic extremists and attempting to restore democracy or civilized form of government to the war-torn nation.