Group →	7
↓ Period
4 Period 4 element A period 4 element is one of the chemical elements in the fourth row of the periodic table of the elements. The periodic table is laid out in rows to illustrate recurring trends in the chemical behaviour of the elements as their atomic number increases: a new row is begun when chemical behaviour...
5 Period 5 element A period 5 element is one of the chemical elements in the fifth row of the periodic table of the elements. The periodic table is laid out in rows to illustrate recurring trends in the chemical behaviour of the elements as their atomic number increases: a new row is begun when chemical behaviour...
6 Period 6 element A period 6 element is one of the chemical elements in the sixth row of the periodic table of the elements, including the lanthanides...
7 Period 7 element A period 7 element is one of the chemical elements in the seventh row of the periodic table of the chemical elements. The periodic table is laid out in rows to illustrate recurring trends in the chemical behaviour of the elements as their atomic number increases: a new row is begun when chemical...

A Group 7 element is one in the series of elements

Chemical element

A chemical element is a pure chemical substance consisting of one type of atom distinguished by its atomic number, which is the number of protons in its nucleus. Familiar examples of elements include carbon, oxygen, aluminum, iron, copper, gold, mercury, and lead.As of November 2011, 118 elements...

 in group 7

Periodic table group

In chemistry, a group is a vertical column in the periodic table of the chemical elements. There are 18 groups in the standard periodic table, including the d-block elements, but excluding the f-block elements....

 (IUPAC style) in the periodic table

Periodic table

The periodic table of the chemical elements is a tabular display of the 118 known chemical elements organized by selected properties of their atomic structures. Elements are presented by increasing atomic number, the number of protons in an atom's atomic nucleus...

, which consists of manganese

Manganese

Manganese is a chemical element, designated by the symbol Mn. It has the atomic number 25. It is found as a free element in nature , and in many minerals...

 (Mn), technetium

Technetium

Technetium is the chemical element with atomic number 43 and symbol Tc. It is the lowest atomic number element without any stable isotopes; every form of it is radioactive. Nearly all technetium is produced synthetically and only minute amounts are found in nature...

 (Tc), rhenium

Rhenium

Rhenium is a chemical element with the symbol Re and atomic number 75. It is a silvery-white, heavy, third-row transition metal in group 7 of the periodic table. With an average concentration of 1 part per billion , rhenium is one of the rarest elements in the Earth's crust. The free element has...

 (Re), and bohrium

Bohrium

Bohrium is a chemical element with the symbol Bh and atomic number 107 and is the heaviest member of group 7 .It is a synthetic element whose most stable known isotope, 270Bh, has a half-life of 61 seconds...

 (Bh). All known elements of group 7 are transition metals.

Like other groups, the members of this family show patterns in their electron configuration

Electron configuration

In atomic physics and quantum chemistry, electron configuration is the arrangement of electrons of an atom, a molecule, or other physical structure...

s, especially the outermost shells resulting in trends in chemical behavior.

Chemistry

Z Atomic number In chemistry and physics, the atomic number is the number of protons found in the nucleus of an atom and therefore identical to the charge number of the nucleus. It is conventionally represented by the symbol Z. The atomic number uniquely identifies a chemical element...	Element Chemical element A chemical element is a pure chemical substance consisting of one type of atom distinguished by its atomic number, which is the number of protons in its nucleus. Familiar examples of elements include carbon, oxygen, aluminum, iron, copper, gold, mercury, and lead.As of November 2011, 118 elements...	No. of electrons/shell Electron shell An electron shell may be thought of as an orbit followed by electrons around an atom's nucleus. The closest shell to the nucleus is called the "1 shell" , followed by the "2 shell" , then the "3 shell" , and so on further and further from the nucleus. The shell letters K,L,M,.....
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 has been known for millennia. Rhenium was discovered when Masataka Ogawa

Masataka Ogawa

was a Japanese chemist known for the discovery of rhenium, which he named nipponium.After graduating from the University of Tokyo, he studied under William Ramsay in London, where he worked on the analysis of the rare mineral thorianite...

 found what he thought was element 43 in thorianite

Thorianite

Thorianite is a rare mineral, originally discovered by Ananda Coomaraswamy in 1904 as uraninite, but recognized as a new species by Wyndham R. Dunstan. It was so named on account of its high percentage of thorium ; it also contains the oxides of uranium, lanthanum, cerium and didymium...

, 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

Walter Noddack

Walter Noddack was a German chemist. He, Ida Tacke , and Otto Berg reported the discovery of element 43 and element 75 in 1925.-Rhenium:...

, Otto Berg

Otto Berg

Otto Berg may refer to:*Otto Berg , a Norwegian long jumper*Otto Karl Berg, the German botanist who named the Feijoa*Otto Berg , the German scientist who co-discovered Rhenium...

, 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

Carlo Perrier

Carlo Perrier was an Italian mineralogist who did extensive research on the element technetium in 1936. He discovered the element along with his colleague, Emilio Segrè , in 1937....

 and Emilio Segré, who discovered Technetium-95 and Technetium-97. Bohrium was discovered in 1981 by a team led by Peter Armbruster

Peter Armbruster

Peter Armbruster is a physicist at the Gesellschaft für Schwerionenforschung facility in Darmstadt, Germany, and is credited with co-discovering elements 107 , 108 , 109 , 110 , 111 , and 112 with research partner Gottfried Münzenberg.He studied physics at the Technical...

 and Gottfried Münzenburg by bombarding Bismuth-209

Bismuth-209

Bismuth-209 is the isotope of bismuth with the longest half-life. It has 83 protons and 126 neutrons, and an atomic mass of 208.9803987 u. All primordial bismuth is of this isotope...

 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

Spontaneous fission

Spontaneous fission is a form of radioactive decay characteristic of very heavy isotopes. Because the nuclear binding energy reaches a maximum at a nuclear mass greater than about 60 atomic mass units , spontaneous breakdown into smaller nuclei and single particles becomes possible at heavier masses...

; almost all is produced in laboratories. Bohrium is only produced in nuclear reactors and has never been isolated in pure form.

Biological Occurrence

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 chloroplast

Chloroplast

Chloroplasts are organelles found in plant cells and other eukaryotic organisms that conduct photosynthesis. Chloroplasts capture light energy to conserve free energy in the form of ATP and reduce NADP to NADPH through a complex set of processes called photosynthesis.Chloroplasts are green...

s. Technetium, Rhenium, and Bohrium have no known biological roles.

Explanation of right side periodic table slice:

Transition metal Transition metal The term transition metal has two possible meanings:*The IUPAC definition states that a transition metal is "an element whose atom has an incomplete d sub-shell, or which can give rise to cations with an incomplete d sub-shell." Group 12 elements are not transition metals in this definition.*Some... s

atomic number in black are solids

solid borders are older than the Earth Earth Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...  (Primordial elements)

dotted borders are made artificially (Synthetic element Synthetic element In chemistry, a synthetic element is a chemical element that is too unstable to occur naturally on Earth, and therefore has to be created artificially. So far 30 synthetic elements have been discovered—that is, synthesized... s)

dashed borders have no isotopes older than the earth