P block elements Group 17 elements

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P - Block Elements

 Group 17 elements -


   The non-metallic elements Chlorine, fluorine, bromine, iodine and astatine constitute group VIIA or 17 of the periodic table. These are collectively known as Halogens as their salts are present in sea water (Greek:halo = sea salt, genes = producing). They have one electron less than the nearest noble gas elements, for which they exist as non-metals. These are highly electronegative elements and thus are very reactive in nature. Fluorine, the first number of the element is the most reactive element because of its highest electronegativity value. Astatine the last member of halogen family is a radioactive element which has very short life period.

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Siemens Ozoniser how Siemens Ozoniser work

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Rutile structure

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Rutile structure: The radius radio is in the range 0.73 to 0.41. in rutile (TiO²) each Ti⁴+ ion is octahedrally surrounded by six O²- ions whereas each other O²- ion is surrounded by only three Ti⁴+ ions arranged at the tree corners of a plane triangle. The Co-ordination number of Ti⁴+ and O²+ ions are 6 and 3, respectively. It is not exactly a close packed structure. Ti⁴+ ions in rutile may however, be considered as forming a sufficiently distorted body centred cubic lattice.           Example  compounds  having radius ratio below 0.41 are SiO² and BeF² but these are only a few. The Co-ordination number of Si⁴+ and Be²+ is four and that of O²- is two. However, these are appreciably co-valent.
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Paramagnetic substances

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