How many nearest neighbours are there for Si and O atoms in quartz crystals?

Options

A. `4(Si), 2(O)`
B. `4(Si), 4(O)`
C. `2(Si), 2(O)`
D. `3(Si), 2(O)`

Answer

A

Explanation

Quariz is ` SiO_(2)` (silicon dioxide) in which ` SiO_(2)` units are present as gaint crystal . In ` SiO_(2)` crystal each Si-atom is surrounded by 4 (O-atom) , i.e. has four nearest neighbours and each O-atom is surrounded by two Si-atoms having two nearest neighbours .

Hence, option (a) is correct .