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The name 'silica' covers an entire group...

The name 'silica' covers an entire group of minerals which have the general formula `SiO_2` the most tetrahedra arranged in spirals . The spirals can turn in a clockwise or anti-clockwise direction - a feature that results in these being two mirror images optically active,
varieties of quartz.
`Si_3O_9^(6-)` (having three tetrahedra ) is represented as :

A

B

C

both

D

none

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The correct Answer is:
A
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The name 'silica' covers an entire group of minerals which have the general formula SiO_2 the most tetrahedra arranged in spirals . The spirals can turn in a clockwise or anti-clockwise direction - a feature that results in these being two mirror images optically active, varieties of quartz. The following pictures represent various silicate anions. Their formulae are respectively : .

The name 'silica' covers an entire group of minerals, which have the general formula SiO_(2) , the most common of which is quartz. Quartz is a framwork silicate with SiO_(4) tetrahdera arranged in spirals. the spirals can turn in a clockwise or anticlockwise direction-a feature that results in there being two mirror images, optically active, varieties of quartz. In the given following emperical formulae of silicates shared and unshared oxygen corner are same by each tetrahedron in.

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