Group+09

Group 9 By Erin M.

Elements in Group:
 * Cobalt
 * Rhodium
 * Iridium
 * Meitnerium


 * All of the elements located in this group are transition metals. **

 Symbol-Co Atomic Number-27 Atomic Mass-58.9 Isotopes- 8
 * Cobalt **



Cobalt was discovered in 1735 by a Swedish chemist named Georg Brandt. Cobalt is a metallic gray color. It's melting point is 1495º C and it's boiling point is 2927º C. It is a solid at room temperature. Cobalt has a density of 8.86 grams per cubic cm. It is ductile, malleable and can conduct both heat and electricity. However it is not flammable or soluble in water or oxygen. Cobalt is used for making jet engines and gas turbine parts and strong permanent magnets. Cobalt and compounds of cobalt are used in the pigmentation paints. Cobalt blue is the most common compound used for this.

Rhodium ** Symbol- Rh Atomic Number-45 Atomic Mass-102.9 Isotopes-9
 * 

Rhodium was discovered in 1803 by William Hyde Hollaston in England. Rhodium has a melting point of 1964º C and a boiling point of 3695º C. It is a good electrical conductor, malleable and ductile, but not flammable or soluble in water or oxygen. It is a solid at room temperature and has a density of 12.41 grams per cubic cm.

It is a hard silvery white and durable metal used as a electiral conductor, making jewelry, and helps give white gold an extra shine. Along with iridium, it also hardens platinum. **__ Rhodium historically was six times more expensive than gold.

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 * 

Iridium ** Symbol-Ir Atomic Number-77 Atomic Mass-192.2 Isotopes-11

Iridium is white and resembles platnium, but also has a slightly yellowish cast. It has a high boiling point of 4428º C and a melting point of 2466º C. Iridium is also a very brittle metal, it is also not flammable. However it is still malleable, ductile and a good conductor of both heat and electricity. It has a density of 22.56 grams per cubic cm. At room temperature, it is a solid.


 * __Iridium is the most corrosion resistant metal known__**. It can not be attacked by any acid or molten metals. However, it can be soluble in certain molten salts, and at the right temperature, even oxygen. It is used to make hypodermic needles, helicopter spark plugs and, similar to rhodium, is a hardening agent for platinum.

**

Meitnerium ** Symbol-Mt Atomic Number-109 Atomic Mass-265.9 Isotopes-1



This element does not occur naturally. Meitnerium was first synthesized on August 29,1982 at the Institute for Heavy Ion Research in Darmstadt, Germany. The name came from honoring an Austrian physicist named Lise Meitner. **__Before this name became the official title in 1997, the element was called eka-iridium__**.