If a trivalent atom replacesafew silicon atoms in three dimensional networkof silicon dioxide, what would be the type ofcharge on overall structure ?

If a trivalent atom replacesafew silicon atoms in three dimensional ne

1.	If a trivalent atom replacesafew silicon atoms in three dimensional networkof silicon dioxide, what would be the type ofcharge on overall structure ?
Answer» Solution :If a few tetrahedral silicon atoms ina three-dimensional networkstructureof `SiO_(2)`is REPLACEDBY an equalnumber of TRIVALENT atoms, then one VALENCY of each siliconatom becomesfree. In other words, each substitutionof siliconatom by a trivalentatom introducesone unit negative CHARGE into the three-dimensionalnetworkstructure of `SiO_(2)`. Thus. `SiO_(2)` becomes negatively CHARGED.