Page 11 - Curriculum Visions Dynamic Book

Rb see Rubidium; Re see Rhenium; Rf see Rutherfordium, Rh see Rhodium Rhenium (Re)
Element 75. A very dense, silvery- white, and extremely hard metal belonging to the transition metals in the Periodic Table. It is the densest metal after platinum, iridium and osmium. It has the highest melting point except for tungsten and carbon.
Discovery
It was predicted in 1871 by Mendeleev as a result of the construction of the Periodic Table. Its properties were supposed to be similar to manganese. However, it was only discovered in 1925 as small amounts in the ore tantalite by the German chemists Ida and Walter Noddack and Otto Carl Berg.
Technology
Used in trace amounts in alloying metals to make them wear resistant. It is used in fountain pen nibs and similar applications. It resists being pitted by electric sparks and so is an electrical contact material. It is also in lamp filaments, in welding rods and thermocouples.
Geology
Rhenium does not occur as a native element. It is found in tiny amounts in tantalite, and more substantially in molybdenite, beryllium and copper sulphide ores. It is obtained as a by-product from the refining of molybdenum ores.
Biology
It is not found in living things.
Key facts...
Name: rhenium
Symbol: Re
Atomic number: 75
Atomic weight: 186.2
Position in Periodic Table: transition metal,
group (7) (manganese group); period 6 State at room temperature: solid
Colour: silvery-white
Density of solid: 21.5 g/cc
Melting point: 3,180°C
Boiling point: 5,627°C
Origin of name: from the Latin word Rhenus,
meaning river Rhine
Shell pattern of electrons: 2–8–18–32–13–2
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