Group 9 element

Group 9 element
Group → 4
↓ Period
4 Cobalt, electrolytic made, 99,9%
27
Co
5 Rhodium, powder, pressed, remelted 99,99%
45
Rh
6 Pieces of pure iridium
77
Ir
7 109
Mt

Legend
Transition metal
Primordial element
Synthetic


In modern IUPAC nomenclature, Group 9 of the periodic table contains the elements cobalt (Co), rhodium (Rh), iridium (Ir), and meitnerium (Mt). These are all d-block transition metals. All known isotopes of Mt are radioactive with short half-lives, and it is not known to occur in nature; only minute quantities have been synthesized in laboratories.

Like other groups, the members of this family show patterns in its electron configuration, especially the outermost shells resulting in trends in chemical behavior, though rhodium curiously does not follow the pattern:

Contents

Chemistry

H   He
Li Be   B C N O F Ne
Na Mg   Al Si P S Cl Ar
K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe
Cs Ba * Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn
Fr Ra ** Rf Db Sg Bh Hs Mt Ds Rg Cn Uut Uuq Uup Uuh Uus Uuo
 
  * La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
  ** Ac Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr
Group 9 in the periodic table
Z Element No. of electrons/shell
26 cobalt 2, 8, 15, 2
44 rhodium 2, 8, 18, 16, 1
76 iridium 2, 8, 18, 32, 15, 2
108 meitnerium 2, 8, 18, 32, 32, 15, 2

Meitnerium has not been isolated in pure form, and its properties have not been conclusively observed; only cobalt, rhodium, and iridium have had their properties experimentally confirmed. All three elements are typical silvery-white transition metals, hard, and have high melting and boiling points.

History

Cobalt has been discovered in Egyptian and Persian artifacts from before the 2nd millenium BCE. Rhodium was discovered in 1803 when William Hyde Wollaston dissolved platinum ore in aqua regia, then neutralized the acid with sodium hydroxide. Wollaston then added ammonium chloride, and dissolved all metals except rhodium and palladium with the nitric acid in the aqua regia. Iridium was discovered in a very similar way in 1804 by Smithson Tennant. Meitnerium was discovered in 1982 by bombarding bismuth-209 with iron-58.

Occurrence

All group 9 elements are relatively rare in the earth's crust, with the most abundant, cobalt, only accounting for 0.0029% of the Earth's crust. Rhodium and Iridium are two of the rarest naturally occurring elements in the earth, only found in platinum ores. Meitnerium has only been produced in nuclear reactors and has never been observed in nature nor isolated in pure form.

Biological occurrence

Cobalt is an essential trace nutrient to all animals, found in vitamin B-12. Rhodium, Iridium, and Meitnerium have no known biological roles.

Applications

  • Alloys with other metals, primarily to add corrosion and wear resistance
  • Industrial Catalysts
  • Superalloys
  • Electrical Components

See also

Explanation of right side periodic table slice: Transition metals atomic number in black are solids solid borders are older than the Earth (Primordial elements) dashed borders have no isotopes older than the earth

Wikimedia Foundation. 2010.

Игры ⚽ Поможем сделать НИР

Look at other dictionaries:

  • Group 6 element — Group → 6 ↓ Period 4 24 Cr 5 …   Wikipedia

  • Group 7 element — Group → 7 ↓ Period 4 25 Mn 5 …   Wikipedia

  • Group 11 element — Group → 11 ↓ Period 4 29 Cu 5 …   Wikipedia

  • Group 10 element — Group 10 redirects here. For the rugby league competition, see Group 10 Rugby League. Group → 4 ↓ Period 4 …   Wikipedia

  • Group 8 element — Group 8 redirects here. For the Swedish organization, see Group 8 (Sweden). A Group 8 element is one in the series of elements in group 8 (IUPAC style) in the periodic table, which consists of the transition metals iron (Fe), ruthenium (Ru),… …   Wikipedia

  • Group 12 element — A group 12 element is one in the series of elements in group 12 (IUPAC style) in the periodic table, consisting of transition metals which are zinc (Zn), cadmium (Cd), mercury (Hg), and ununbium (Uub). When compared with other groups of… …   Wikipedia

  • Group 5 element — A Group 5 element is one in the series of elements in group 5 (IUPAC style) in the periodic table, which consists of vanadium (V), niobium (Nb), tantalum (Ta), and dubnium (Db).All of these elements are classed in Group 5 because their valence… …   Wikipedia

  • Group 3 element — || Group 3/ungrouped | 7 || **ActinidesThe Group 3 elements are chemical elements comprising the third vertical column of the periodic table. IUPAC has not recommended a specific format for the periodic table, so different conventions are… …   Wikipedia

  • Group 4 element — In modern IUPAC nomenclature, Group 4 of the periodic table contains the following chemical elements: * titanium (Ti) * zirconium (Zr) * hafnium (Hf) * rutherfordium (Rf).This group lies in the d block of the periodic table. The group itself has… …   Wikipedia

  • Group 1 — * Group 1 element an element classification for Alkali metal * Group 1 (racing) a FIA classification for auto racing that preceded Group N * Group 1 thoroughbred horse races, are the leading events in the sport. * Group 1 Automotive a publicly… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”