What is the chief constituent of Pyrex glass?

Reaction of an inorganic sulphite $X$ with dilute $H_{2}SO_{4}$ generates compound $Y$. Reaction of $Y$ with $NaOH$ gives $X$. Further,the reaction of $X$ with $Y$ and water affords compound $Z$. $Y$ and $Z$,respectively,are:

Under hydrolytic conditions,the compounds used for preparation of linear polymer and for chain termination,respectively,are

Which of the following is not correct?

The element that does $NOT$ show catenation is

$C_{60}$ contains: