Question 1: Define a fullerene and describe its molecular structure.

Answer: A fullerene is a molecule composed entirely of carbon, shaped like a hollow sphere, ellipsoid, or tube, with a structure made up of pentagons and hexagons similar to a soccer ball.

Question 2: Explain how covalent bonding contributes to the stability of graphene sheets.

Answer: Covalent bonds between carbon atoms in graphene form a strong, delocalized network, giving it high strength, stability, and excellent electrical conductivity.

Question 3: What is the primary difference between fullerenes and graphene in terms of structure?

Answer: Fullerenes are spherical or ellipsoidal molecules made of carbon, while graphene is a single, flat sheet of carbon atoms arranged in a hexagonal lattice.

Question 1: Calculate the surface area of a spherical fullerene molecule with a diameter of 1.0 nanometer. Use the formula for surface area of a sphere: A = 4πr². (π ≈ 3.14)

Answer: Surface area ≈ 12.56 nm²

Question 2: If a graphene sheet has a length of 5 meters and a width of 2 meters, what is its total area in square meters?

Answer: 10 m²

Question 1: Describe a simple experiment to test the electrical conductivity of graphene. Include the variables you would control and measure.

Answer: Set up a circuit with graphene as a conductor, control the temperature and contact points, and measure the current flow when a voltage is applied to assess conductivity.

Question 2: Name two industries where fullerenes are used and explain their roles.

Answer: Fullerenes are used in drug delivery systems for medicine and in lubricants due to their unique spherical shape and ability to withstand high pressures.

Question 1: A sample of fullerenes contains 60 carbon atoms. Calculate the approximate molecular mass of this fullerene. (Atomic mass of carbon ≈ 12.01 u)

Answer: Molecular mass ≈ 720.6 u

Question 2: A researcher finds that a graphene sheet can conduct electricity efficiently even when stretched by 10%. Explain how the structure of graphene allows this property.

Answer: The strong covalent bonds in the hexagonal lattice provide flexibility and strength, allowing graphene to stretch without breaking while maintaining electrical conductivity.

Question 1: Describe how the unique properties of fullerenes could be utilized in medicine.

Answer: Fullerenes can be used in targeted drug delivery because their hollow structure allows them to carry medicinal molecules directly to specific cells, reducing side effects and increasing treatment efficiency.

Question 2: Considering environmental concerns, discuss how graphene could be used to improve water filtration systems.

Answer: Graphene's high surface area and ability to form selective membranes enable it to filter out contaminants efficiently, making it a promising material for advanced water purification technologies while also being lightweight and durable.