Which of the following glass is used in making the windscreen of automobiles?

When mechanical stress is applied to a crystal,a small amount of electricity is produced. This property is called ........

Why are liquids and gases called fluids while solids are rigid?

Why are solids rigid?

Graphite and Cinnabar are examples of $.......$ and $.......$ crystal systems,respectively.

Classify each of the following solids as ionic,metallic,molecular,network (covalent) or amorphous.
$(i)$ Tetra phosphorus decoxide $(P_{4}O_{10})$ $(ii)$ Ammonium phosphate $(NH_{4})_{3}PO_{4}$
$(iii)$ $SiC$ $(iv)$ $I_{2}$ $(v)$ $P_{4}$ $(vi)$ Plastic $(vii)$ Graphite $(viii)$ Brass $(ix)$ $Rb$ $(x)$ $LiBr$ $(xi)$ $Si$