RAS question
Graphene, a nanomaterial, is a single layer of:
Correct answer: (B) Carbon atoms arranged in a hexagonal lattice.
Graphene is a single layer of carbon atoms arranged in a two-dimensional hexagonal, or honeycomb, lattice.
Explanation
Graphene is not a generic nanoparticle or a metal sheet; it is a two-dimensional crystalline form of carbon. Encyclopaedia Britannica describes graphene as either a single layer of carbon atoms forming a honeycomb, hexagonal lattice, or several coupled layers of that structure, and notes that the word usually means single-layer graphene unless another form is specified. The MCQ's wording points to a nanomaterial made from one atomic layer of carbon atoms arranged in a two-dimensional hexagonal lattice. This atomic arrangement also explains why graphene is treated as a distinctive material in science and technology questions: it is linked with extreme thinness, high strength, and excellent electrical and thermal conductivity.
Why the other options are wrong
- (A) Gold nanoparticles are the wrong material class because graphene is a crystalline form of carbon, not a layer made from gold particles.
- (C) Iron atoms do not define graphene; graphene's structure is built from carbon atoms arranged in a hexagonal lattice.
- (D) Silicon atoms are not graphene's composition; graphene is carbon-based, although silicene is a silicon analogue.
Concept
This tests the Science and Technology concept of nanomaterials and carbon allotropes. It recurs in RAS because graphene is a compact example linking atomic structure with material properties such as strength and conductivity.