Question

Which of the following is used for making optical instruments?
A.$Si{O_2}$
B.Si
C.$Si{H_4}$
D.SiC

Answer 1

Flint glass or optical glass use the components silicates and potassium and have a chemical formula ${K_2}O$ . $P{b_2}O$ . $4Si{O_2}$ Silica is an important ingredient to make glass, which is extensively used in the making of optical devices.

Complete step by step answer:
Optical instruments are the devices that process light waves to enhance the look of an image for a clear view. Besides magnifying the distant or tiny images, these devices are used to analyse the properties of optical materials and light. The use of optical instruments, such as a magnifying lens or any complicated device like a microscope or telescope, usually makes things bigger and helps us to see in a more detailed manner. The use of converging lenses makes things appear larger, and on the other hand, diverging lenses always get you smaller images.
Silica is an important ingredient which is widely used to make glass, which is extensively used in the making of optical devices. A clear, strong glass is produced when pure silica is fused at a high temperature. Thus, amorphous silicon dioxide $(Si{O_2})$ is used in making optical instruments either as pure substances or with a mixture with other additional compounds which will lead to materials like borosilicate, aluminosilicates etc.

Therefore, the correct answer is option (A).

Note: We can also get confused with Silane $(Si{H_4})$ but it is used as a coupling agent to bind fibres such as glass fibres and carbon fibres to certain polymer matrices, stabilising the composite material. It is also used for coating glass fibres to create better adhesion to the polymer matrix.