Group 7 element

Group 7, numbered by IUPAC nomenclature, is a group of elements in the periodic table. They are manganese (Mn), technetium (Tc), rhenium (Re), and bohrium (Bh). All known elements of group 7 are transition metals.

Like other groups, the members of this family show patterns in their electron configurations, especially the outermost shells resulting in trends in chemical behavior.

Group 7 in the periodic table
Hydrogen Helium
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon
Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon
Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon
Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson
group 6  group 8
IUPAC group number 7
Name by element manganese group
CAS group number
(US, pattern A-B-A)
VIIB
old IUPAC number
(Europe, pattern A-B)
VIIA

↓ Period
4
Manganese
Manganese (Mn)
25 Transition metal
5
210px alt=Image:
Technetium (Tc)
43 Transition metal
6
Rhenium bar
Rhenium (Re)
75 Transition metal
7 Bohrium (Bh)
107 Transition metal

Legend

primordial element
element by radioactive decay
synthetic element
Atomic number color:
black=solid

Chemistry

Z Element No. of electrons/shell
25 manganese 2, 8, 13, 2
43 technetium 2, 8, 18, 13, 2
75 rhenium 2, 8, 18, 32, 13, 2
107 bohrium 2, 8, 18, 32, 32, 13, 2

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

History

Group 7 contains the two naturally occurring transition metals discovered last: technetium and rhenium. Manganese was discovered much earlier owing to its much larger abundance in nature. Rhenium was discovered when Masataka Ogawa found what he thought was element 43 in thorianite, but this was dismissed; recent studies by H. K. Yoshihara suggest that he discovered rhenium instead, a fact not realized at the time. Walter Noddack, Otto Berg, and Ida Tacke were the first to conclusively identify rhenium; it was thought they discovered element 43 as well, but as the experiment could not be replicated, it was dismissed. Technetium was formally discovered in December 1936 by Carlo Perrier and Emilio Segré, who discovered Technetium-95 and Technetium-97. Bohrium was discovered in 1981 by a team led by Peter Armbruster and Gottfried Münzenburg by bombarding Bismuth-209 with Chromium-54.

Occurrence

Manganese is the only common Group 7 element. In 2007 11 million metric tons of manganese were mined. All other elements are either incredibly rare on earth (technetium, rhenium) or completely synthetic (bohrium). In contrast to manganese, only 40 or 50 metric tons of rhenium were mined. Technetium is only found in trace amounts in nature as a product of spontaneous fission; almost all is produced in laboratories. Bohrium is only produced in nuclear reactors and has never been isolated in pure form.

Production

Manganese

In 2007, 11 million metric tons of manganese were mined.

Technetium

Ruthenium

Bohrium

Bohrium is a synthetic element that does not occur in nature. Very few atoms have been made, but due to its radioactivity, only limited research has been made.

Applications

Manganese

Technetium

Technetium is used in radioimaging.

Ruthenium

Bohrium

Bohrium is a synthetic element and is too radioactive to be used in anything.

Precautions

Although being an essential trace element in the human body, manganese can be somewhat toxic if ingested in higher amounts than normal. Technetium should be handled with care due to its radioactivity.

Biological role and precautions

Only manganese has a role in the human body. It is an essential trace nutrient, with the body containing approximately 10 milligrams at any given time, being mainly in the liver and kidneys. Many enzymes contain manganese, making it essential for life, and is also found in chloroplasts. Technetium, rhenium, and bohrium have no known biological roles. Technetium is however used in radioimaging.

Bohrium

Bohrium is a synthetic chemical element with symbol Bh and atomic number 107. It is named after Danish physicist Niels Bohr. As a synthetic element, it can be created in a laboratory but is not found in nature. It is radioactive: its most stable known isotope, 270Bh, has a half-life of approximately 61 seconds, though the unconfirmed 278Bh may have a longer half-life of about 690 seconds.

In the periodic table of the elements, it is a d-block transactinide element. It is a member of the 7th period and belongs to the group 7 elements as the fifth member of the 6d series of transition metals. Chemistry experiments have confirmed that bohrium behaves as the heavier homologue to rhenium in group 7. The chemical properties of bohrium are characterized only partly, but they compare well with the chemistry of the other group 7 elements.

Group 7

Group 7 may refer to:

G7, an international group of finance minister

Group 7 element, chemical element classification

Halogens (alternative name)

Group 7 Rugby League, rugby league competition in New South Wales, Australia

Group 7 (racing), FIA classification for Can-Am sports car racing

Group Seven Children's Foundation, charitable organization

Group of Seven (disambiguation)

The Group of Seven (G7) is an international forum consisting of the seven nations with the largest advanced economies – Canada, France, Germany, Italy, Japan, the United Kingdom, and the United States – and the European Union.

Group of Seven may also refer to:

Group of Eight, the name used by the G7 forum before the expulsion of Russia

Group of Seven (artists), a group of Canadian landscape painters 1920 to 1933, originally including Franklin Carmichael, Lawren Harris, A. Y. Jackson, Frank Johnston, Arthur Lismer, J. E. H. MacDonald, and Frederick Varley

Group of Seven, or Metcalf Chateau, a group of American artists with ties to Honolulu, including Satoru Abe, Bumpei Akaji, Edmund Chung, Tetsuo Ochikubo, Jerry T. Okimoto, James Park, and Tadashi Sato

Group 7 element, a group of elements in the periodic table

Ida Noddack

Ida Noddack (25 February 1896 – 24 September 1978), née Tacke, was a German chemist and physicist. In 1934 she was the first to mention the idea later named nuclear fission. With her husband Walter Noddack she discovered element 75, rhenium. She was nominated three times for the Nobel Prize in Chemistry.

Index of chemistry articles

Chemistry (from Egyptian kēme (chem), meaning "earth") is the physical science concerned with the composition, structure, and properties of matter, as well as the changes it undergoes during chemical reactions.Below is a list of chemistry-related articles. Chemical compounds are listed separately at list of organic compounds, list of inorganic compounds or list of biomolecules.

Oxyacid

An oxyacid, or oxoacid, is an acid that contains oxygen. Specifically, it is a compound that contains hydrogen, oxygen, and at least one other element, with at least one hydrogen

Periodic table forms
Sets of elements
Elements
History
See also
Group 7 elements

This page is based on a Wikipedia article written by authors (here).
Text is available under the CC BY-SA 3.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.