Osmium metal

Osmium metal
Osmium (Greek: mememe osμα - osidum; Latin: Osmium) is a chemical element belonging to group VIII of the Os-Mendeleev periodic table. Sequence number 76, atomic mass, 190.2. Natural Osmium consists of 7 stable isotopes: l84Os (0.018%), l86Os (l, 59%), 187Os (l, 64%), 188Os (13.3%), 189Os (16, l%), 190Os (26, 4%), 192Os (41, l%). Among the artificial radioactive isotopes of osmium, 184Os is the longest (T | / 2 = 700 days). Osmium was discovered in 1804 by Osmium Tennant in the composition of substances left over from the dissolution of platinum in gold. Osmium's OsO4 anhydride has a pungent odor (similar to that of chlorine), and powdery osmium has a similar odor. In terms of the mass of the Earth's crust. 5-10 ~ 6% nitash. In nature, in the form of an alloy with iridium, it is found in ores of platinum group metals. In Uzbekistan, polymetallic ores from Almalyk and Kyzylkum regions are scattered.
Osmium is a bluish solid metal. The heaviest of the metals. Density 22.6 g / cm3 (at 15 °), liquidus temperature 3027 °, boiling point 5027 °. Osmium differs sharply from other metals in the platinum group in terms of chemical properties; it sometimes exhibits non-metallic properties. When osmium is heated in air, it oxidizes to OsO4 - osmium (USH) oxide.
Osmium has 2,4 and 8 valence oxides. Osmium oxides are volatile at 600-950 °. Osmium monoxide or osmium (P) -oxide, OsO is a black powder, insoluble in water and acids, oxidizes very quickly. Osmium (I V) - o k -sid, OsO2 is a brown or black powdery substance, insoluble in water and dilute acids, density 7.91 g / cm3 (at 22 °), decomposes at 650 °. When heated in air, it converts to osmium (USH) oxide. Osmium (USH) -oxide or osmium anhydride OsO4 is a colorless crystalline substance, density 4.96 g / cm3 (at 22 °), liquidus temperature 39.5 °, boiling point 130 °. Poisonous. Soluble in water, alcohol and ether. The solution in water is called osmotic acid H2 [OsO4 (OH) 2]. When the metal Osmium powder is heated to 250 ° with fluorine, osmium (VIII) - fluoride is converted to OsF3. Additionally, OsF6 and OsF4 xdm appear. When osmium chloride is heated in an atmosphere, OsCl4, OsClj, OsCl2 are formed.
Osmium is separated from platinum group ores and copper molybdenum ores by platinum group metals. When separated from other metals, OsO4 is transferred to another vessel. Osmium alloys are used in the manufacture of precision measuring instruments, radio engineering, composite materials, and their compounds are used as catalysts in medicine and photography .
Questions :

1. 
   What are the chemical properties of osmium?
   
2. 
   Which is occurs in osmium nature?
   
3. 
   What is metall osmium?
   
4. 
   What are the physical properties of osmium?
   
5. 
   What are the valence oxides of osmium?
   

Tests:

1. 
   What is the ordinal number of the osmium element?
   

A)76 B)67 C)88

2. 
   What is the atomic mass of osmium ?
   

A)180 B)190.2 C) 100

3. 
   What is the density of osmium?
   

A)7.5 B)8.4 C)4.96

4. 
   What is the boiling point of osmium ?
   

A)130 B)100 C)120

5. 
   What is the liquefaction temperature of osmium?
   

A)30.3⁰ C B)39.5⁰C C)40.7⁰C

Vocabulary :

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  Volatile- uchuvchan
  
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  Separate- alohida
  
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  Poisonous-zararli
  
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  Polymetallic- polimetall
  
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  Sequence- tartib