What are the chemical properties of group 7 elements?

Answer 1

If I had to guess I'd say it has something to do with maybe gasses an/or lights.(just a guess)

here is some info I found though.....

http://en.wikipedia.org/wiki/Group_7_element

A Group 7 element is one in the series of elements in group 7 (IUPAC style) in the Periodic Table, which consists of the transition metals manganese (Mn), technetium (Tc), rhenium (Re), and bohrium (Bh). Like other groups, the members of this family show patterns in its electron configuration, especially the outermost shells resulting in trends in chemical behavior: {| ! 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 All of these elements are classed in Group 7 because their valence shells hold seven electrons. Technetium has no stable isotopes. Technetium and promethium are the only two such elements before lead, after which (with bismuth having an extremely long-lived isotope) no known element has a stable isotope.

http://www.chemguide.co.uk/inorganic/group7menu.html

PERIODIC TABLE GROUP 7 (HALOGENS) MENU ;

Atomic and physical properties . . .

: Discusses trends in atomic radius, electronegativity, electron affinity and melting and boiling points of the Group 7 elements. It also looks at the bond strengths of halogen-halogen bonds and of hydrogen-halogen bonds. ;

Halogens as oxidising agents . . .

: Describes and explains the trend in oxidising ability of the Group 7 elements based on the reactions between one halogen and the ions of another one - for example, between Cl2 and I- ions from salts like KI. ;

The acidity of the hydrogen halides . . .

: Discusses the acidity of the hydrogen halides (like hydrogen chloride), and explains why HF is a weak acid. ;

Halide ions as reducing agents . . .

: Describes and explains the trend in reducing ability of the halide ions based on their reactions with concentrated sulphuric acid. ;

Testing for halide ions . . .

: Describes and explains the tests for halide ions using silver nitrate solution followed by ammonia solution. ;

The manufacture of chlorine . . .

: Describes the manufacture of chlorine by the electrolysis of sodium chloride solution using a diaphragm cell and a membrane cell. |}

Answer 2

known as the halogens, exist as discrete, diatomic molecules. Highly reactive elements. Flourine is the most electronegative element. Flourine and chlorine exist as gases, bromine as a liquid and iodine as a solid.

Answer 3

"Group 7" now usually refers to manganese, technetium, rhenium, and bohrium. Neither technetium nor bohrium has any non radioactive isotopes. The other two are moderately reactive metals characterized by stable oxyanions in which the oxidation number of the metal is usually +5 or +7. Manganese also has +2 and +4 oxidation states as a cation.

In the narrow form periodic table style commonly used fifty years, "Group VII" also includes the halogens, fluorine, chlorine, bromine, iodine, and (presumably) astatine, which are non metals and form mono atomic anions with an oxidation state of -1 for the halogen. As elements, they all form diatomic molecules. They also form bonds to carbon in organic compounds, and all of them except fluorine form oxyanions in which the halogen has a positive oxidation number, up to +7. They also form numerous oxides and inter halogens.