Explanation:

• Graphene is a single layer (monolayer) of carbon atoms. It is one atom thick. It is the building-block of Graphite.
• It is harder than diamond yet more elastic than rubber; tougher than steel yet lighter than aluminium.
• It is the strongest known material.
• Allotropes of carbon: Diamond, graphite and fullerenes (substances that include nanotubes and buckminsterfullerene) are the important allotropes of pure carbon.

Other Properties of Graphene are:

• Lowest resistivity substance known at room temperature.
• High thermal stability.
• High elasticity.
• High electrical conductivity.
• Electron mobility is high at room temperature.

Graphene oxide (GO) membranes can be used to filter common salt from seawater.

• Its thin composition and high conductivity means it can be used in applications ranging from miniaturised electronics to biomedical devices like computers, solar panels, batteries, sensors and other devices.

Hence all statements are correct.