Question

Silica in amorphous form is used in:
A. photovoltaic cells
B. conductivity cell
C. standard hydrogen electrode
D. glass electrode

Answer 1

Hint: Solids are of two types-amorphous and crystalline. The term amorphous is used for those solids in which the particles are nor arranged in a regular order. Silica is different from the element silicon. Silica is a compound.

Complete step by step solution:
Silica is a compound having the chemical formula ${\text{Si}}{{\text{O}}_2}$. It is found commonly in crystalline state, but rarely in amorphous state. It is mostly seen in sand. They are of different forms. It is considered as an organic mineral. They are used as health supplements because of its organic nature.
Silica is resistant to heat and it is very hard. So it is used for production of concrete. Silica has a wide variety of uses since it has many properties. They are used in electronic, chemical and pharmaceutical industries.
Amorphous silica is used in photovoltaic cells. Though it has a low efficiency, it is very low power consuming. Also, it is very cheap and its performance is more than that of crystalline solid.
While silver or mercury is used in glass electrodes. Platinum element is used in conductivity cells and standard hydrogen electrodes.
Thus silica in amorphous form is used in photovoltaic cells.
Hence the correct option is A.

Additional information:
Even if silica is ingested, it is not very toxic. But silica dust causes even lung cancer, bronchitis or silicosis.

Note: Silica is also beneficial for bones and joints because our body cannot absorb calcium without the presence of silica. We know that the bones are composed of several minerals like calcium, phosphorus, magnesium etc.