Carbon and its Compounds — Science STD 10 — Question

A solid element X has four electrons in the outermost shell of its atom. An allotrope Y of this element is used as a dry lubricant in machinery and also in making pencil leads.

1. What is element X?
2. Name the allotrope Y.
3. State whether allotrope Y is a good conductor or non-conductor of electricity.
4. Name one use of allotrope Y (other than lubrication and pencil leads)
5. Name two other allotropes of element X.