What do NASA workers need to wear when inside the cleany room of the James Webbster telescope? Why does the room have to be absolutely clean?

Graphite is great lubricant because each carbon atom forms weak covalent bonds with three other carbon atoms.

Diamond and graphite both are entirely made up of carbon but both the elements are completely different because of the bonding of carbon atoms. In graphite the carbon atoms form weak covalent with the other three carbon atom due to which there is less or no force between the atoms, and makes the graphite very soft and slippery, and graphite act as lubricant.